Mayflower Mortgage: Hello and welcome back to Self Builders podcast, the podcast for anyone planning funding or building their own home. If you're working on a modern or eco self-builder, you're probably thinking about insulation levels, air tightness and energy efficiency and trying to keep those running costs down. But there's one part of the process that often doesn't get the attention it deserves and that's ventilation. So welcome this week. I'm your host again, Jack, and we're going to be talking about why modern homes need mechanical ventilation. So what's NVHR? actually does and why the phrase build tight, ventilate right matters more than ever. So I'm joined by Mandip from Solar Crest and they specialize in, well he's going to go through it himself, but specialist in mechanical ventilation with heat recovery and fabric first building performance. So before we get into the detail, Mandip for listeners who might not know about Solar Crest, could you give us a quick overview of who you are, what you do, what Solar Crest does and what you specialize in?

Mandip Bhamra: Yeah, thank you, Jack. That's a nice introduction. So I'm Mandit Bamra and I work for Solar Crest, who we specialize in mechanical ventilation and heat recovery. Very, very dry topic, so I'll try and make it sound interesting. ⁓ My background, I started off with a medical degree, would you believe, ⁓ well over 20 years ago and around about 19, 20 years ago. went into the renewable industry. So I've got a lot of experience with ground source, air source heat pumps, underfloor heating, solar PV and NBHR. Started off in the domestic world and ended up running a net zero company. So I've got experience on schools, hospitals, down to self-build and social housing. So the idea is I use my knowledge. over the past 20 years to help and evaluate and value add ⁓ on each project.

Mayflower Mortgage: And Solar Crest themselves, so what Solar Crest do as a company, what sort of types of projects do typically work on?

Mandip Bhamra: So generally it's the self-build market. mean, mechanical ventilation heat recovery is generally not a retrofit item. anyone doing a deep renovation or a new build. So self-build market or social housing, we can tackle commercial as well, but we're focusing more on the quality rather than going over onto the, you know, very price sensitive projects.

Mayflower Mortgage: Perfect for our, for our lesson. So MVHR, so mechanical ventilation with heat recovery. One of those things that people do hear about when they're planning those eco projects, but don't always really understand. So if someone's early in their self-build journey, how would you explain what it is, what it does without getting too, too technical, which will go way above my head as well.

Mandip Bhamra: Yes. That's a very good question because I do about 10 shows a year, brand design and home build shows. Normally have a unit on my stand and if someone comes to the stand and says what is it? I'll always say if you don't know what it is you don't need it. So is that a heat pump? No. Is that an air conditioning unit? No. So normally with a new build it's a compliance thing. they've been told they need it for part F, you know, need an MVHR. So I have to turn that around to, well, actually you need to invest in this. It's a pair of lungs for the house. So essentially what it does is bring in fresh air, recirculates the damp stale air and takes about 90 % of the heat out of it and brings it back into the property. So that's your mechanical ventilation and heat recovery. On the new build project, the milestone is usually when you don't have trickle vents so every house has to breathe so this mechanically brings it in. There can be other parameters like on ⁓ a block of flats near a busy road you might not be able to open a window or a door because of the noise or pollution levels so you have to be able to deliver all that fresh air without having to open a window or a door.

Mayflower Mortgage: Why is it especially important in modern homes compared to older properties?

Mandip Bhamra: So, well, all properties need to breathe, you know, even if you go back to the Victorian properties. But on a newer build, generally properties are a lot more airtight. We're getting better and better in the UK at that, with standards rising. So the more you insulate, the more you need to ventilate. So that's really key. You don't to be suffocated in your own home.

Mayflower Mortgage: Yeah, keep the air for it. So the simple turns make buildings more airtight. We're making more buildings more airtight to improve the energy efficiency. So we have to replace that natural ventilation that may come with windows and doors to, yeah, so replace it so that leaky homes had in the past.

Mandip Bhamra: Yeah. And also Exactly and actually on most modern buildings I mean your biggest losses are normally ventilation losses so extractor fans, MEVs, so mechanical air extractments in bathrooms so why take out all the heat you should recover it so yeah it gets rid of that problem.

Mayflower Mortgage: The phrase of build type, ventilate, right? What does that mean in practice for, for self-builder designing a home?

Mandip Bhamra: So if you're going to build your own home, number one in today's market, it's going to cost you a lot more than two, three years ago. most clients will know what kitchen they're going to have or bathroom. You know, look at all the aesthetics where you should really be spending money and time on the fabric. So it might not be as sexy, let's face it. You can't really see, you can't see the bling factor, but actually investing in the fabric. mean you've got the lowest possible running costs forever. whether you're building a hundred square meter home or a thousand square meter home at every single price point people do want lower running costs. There's the environmental aspect as well obviously carbon footprint but again going down to the MVHR when you've got an airtight building any heat you generate for your heat emitters you want to recover it. So you want to conserve the energy rather than let it go straight out the vents or windows.

Mayflower Mortgage: And we often speak to people who are excited about sort of some of the tech around eco homes, whether it's heat pumps and solar panels and things like that. But this more comes into sort of the fundamentals of the design. And if it's not right at the fundamental stage, all of the rest of it becomes less effective. that, I getting that right?

Mandip Bhamra: Yeah, yeah absolutely. There's a bit of a sequence so again going back to new inquiries from shows, a client will say right I'm having a heat pump, I'm having solar, loads of batteries, I'm doing a passive house and the term is used very loosely. So what they mean is they're looking at all of that but they don't know how airtight they're going to be. So NVHR is basically part of the fabric. I consider it as part of the bare bones, you don't see it, you just know it's there, it's a pair of lungs for the house. So early implementation is critical, you know, we really have to make sure it complements the build and the design, but once you've got to that level, that's when you should decide whether to have a heat pump or not. The biggest benefit would be you can have the smallest heat pump going basically, because you've already tackled the heat loss. and that's where it becomes more effective. can run it at the lowest flow temperature. Solar panels as well, with your airtight building, you have to look at what your background load is, whether you've got swimming pools, hot tubs. If you don't have a swimming pool or a hot tub, then in the summer months, you're really just looking at hot water and LED lighting generally. So you have to size that accordingly so you get the maximum benefit and spend wisely.

Mayflower Mortgage: don't know why I say so making those things early in the planning stage is fundamental. So the things, that's one thing that always comes up with this podcast is timing and knowing when decisions need to be made. So if you are looking at these types of builds, it's important to consider this technology early rather than sort of leave it, leave it later on and sort of try and, like I said, retrofitting is not really.

Mandip Bhamra: Yeah, yeah, absolutely.

Mayflower Mortgage: the sphere that you're in with these ventilation systems. So just go on that. What happens when it is left too late? So when someone, for example, decides to look at ventilation after planning or once they're already on site.

Mandip Bhamra: Yeah. Good site. Yeah. Right, so I try and encourage clients, if possible, to come to us, even if it's concept design. I'm building a house so you can ⁓ preempt plant room areas, ducting routes. In reality, that doesn't happen. Hi, Mandip, I've built the house, the roof is up. Where can I shove this machine? So plant room area is critical. So normally an architect will put a plant room. But things you should consider, size, because you've got the machine, you've then got your manifolds and ducting routes. Rizers, how do you get from floor to floor? There's part B, fire protection. Do you need fire collars? Do you need dampers? Another issue can be you can't put all the hot plant next to an NVHR unit. So you wouldn't want to put your hot water cylinder right next to the NVHR unit because it can be an overheating risk. the summer months. it's small elements like that even putting a heat pump in you've got your normally a buffer tank expansion vessel and your hot water cylinder. UK homes are not really designed with plant rooms in mind generally the Americans and Canadians are a bit more ahead of the game with their bigger houses and plant room areas. So yeah it is critical to allocate the correct space and also in an area that it's easily accessible for your supply and extract terminals. So even if it's a conversation, not a heavy design, it's always good to know right from the beginning.

Mayflower Mortgage: what you're going to do. I we'll put Solar Crest details on the link on the podcast as well. And those late changes, if you're it sort of, you know, sort of later on down the line, what does it tend to mean? it sort of the compromises will have to be made from in terms of the layout? Is it extra cost rework, know, re re redoing work that's already been done to fit in the systems.

Mandip Bhamra: Yeah, mean cost and compromise. So being able to plan it in and being able to squeeze it in is not very good. It could mean a lowered ceiling or compromising an area dedicated to another function in the house. But when you start off with a new build, generally it's more cost effective because you've got a blank canvas. But if you come in too late,

Mayflower Mortgage: Yep.

Mandip Bhamra: It effectively becomes a retrofit. And I've had this with clients where we've done an estimate two years ago and they've ignored me. And two years later, we're ready. We're always going to have you. And yeah, you just have to, you have to make alterations, but not, just physical things. could be design changes. So the architect might have to go back. Could be structural engineers have to look at how Joyce work and

Mayflower Mortgage: You

Mandip Bhamra: even putting you can't just drill through steels without ruining the structural integrity but if we know these things right from the beginning we can actually put collars in and put provisions right from day one so you don't have to retrofit this so it runs a lot more seamlessly

Mayflower Mortgage: takeaway so far is earlier the better.

Mandip Bhamra: Yeah, absolutely. Even though it's not that interesting. Let's talk about it right from the beginning.

Mayflower Mortgage: It's vital. Yeah, it's absolutely. And then from your experience, what drives the cost of an MVHR system? So where do most people commonly sort of get it wrong or misunderstand the pricing of it? So.

Mandip Bhamra: Another very good question because there's such a big variation in service level. So I always look at cars. So you can have a Dacia Duster, it's got four wheels and a steering wheel and then you can have a Mercedes S-Class, they both do the same thing but one's gonna last a lot longer than the others. I should probably say a vintage Merc built by engineers not engineers. So same with the ventilation market. You've got such a big range of different units. I'm not going to start going through different brand names but as a business we tend to use the Airflow Droid units. They're manufactured in Finland so you could say they're like a melee grade appliance. I'd expect them to last 20 to 25 years as opposed to if you go at the lower end of the market it might last seven to ten years and you're changing your motherboard or a motor. So it's a combination between

Mayflower Mortgage: No.

Mandip Bhamra: the design installation and the product and sizing it correctly. The service levels, so when we look at designs, manufacturers tend to do a very basic 2D model, so maybe an hour on CAD, showing where your supply and ⁓ extract ducting routes can go. It doesn't really show you how to get through steel or how to get from A to B, whereas we'd be looking at a 3D Revit model, so. my design work might take a whole week and we'd be engaging with the architects and the client. It's like having a tailor-made suit rather than off the pegsuit. we're not more expensive, we're just doing a different service level. You've then got different types of ducting, whether you go for spiral steel ducting, which is branch systems, or we use a manifold system with radial smooth ducting. So straight down to commissioning. an installation with heavily project manager, an installation with the 3D modeling and on the commissioning side, we might spend a whole day or two going through every single duct, looking at the sound levels with a 3000 pound ananometer, just going that extra mile knowing that, okay, clients paid a little bit more, but when we leave site, we've got something that's never gonna have to be rectified apart from your annual. Usual maintenance which is filter changes or keeping the filters clean etc. yeah, you've got to choose the right service level. If you go down to the builder route, so my plumber will do it. They'll normally, I mean, they'll do it significantly more cost-effectively, but they're just buying an off-the-shelf kit normally. The installer becomes a designer, so they might do a good job. you're not going to get the sound levels and the performance levels, it's non-comparable. you've got to be careful on what you're after and how you want it to perform because a poorly designed and installed system can be noisy and actually cost quite a lot to run. So...

Mayflower Mortgage: Is that what you see most people trying to save money in the installation side of things? And it costs them more long-term in terms of...

Mandip Bhamra: Yeah, we we We do, we do, especially with contractors. They'll normally, if I lose a project just on cost, I'll say, that's fine. Let me know how you get on and come back with your next project. And they normally do come back with our next project. And I should really write down some case studies and share emails, but on the extreme, it can cost them double or even triple to rectify. Cause you can imagine a house has been built, plasterboard goes up. to rectify anything within the fabric. It's gonna cost a lot of money to pull down ceilings and the homeowner's not gonna be happy, so there's lots of disruption. So it's more about investing right from the beginning and getting it right first time.

Mayflower Mortgage: Yeah, that's a really important point, especially for self builders, trying to sort of value engineer saving money upfront isn't always saving money overall. If you do it right the first time, get it working properly then.

Mandip Bhamra: Yeah, yeah, do also understand, know, ⁓ say a developer needs to make money as well. So that's harder in this market. But if you if you look at say, a kitchen, very easy to change a kitchen or a kitchen appliance. So it is worth reallocating some of your budget towards a fabric and things like NVHR and your heat pumps get get that done correctly.

Mayflower Mortgage: Yes.

Mandip Bhamra: maybe downgrade a kitchen and you can easily change an appliance further down the line. A top-end kitchen is not going to make your food taste any better that's for sure.

Mayflower Mortgage: But a better ventilation system is going to make your house work more efficiently and save you more money in the long run.

Mandip Bhamra: Exactly. Exactly.

Mayflower Mortgage: And that's where technical and sort of the finance side might overlap a little bit. Because often we see, again, for the Mayflower side, we see projects that can get delayed or stressed because costs like the ventilation haven't been properly allowed for early on, either in the bill budget or the cash flow, you know, for people coming to us, you know, a little bit later on down the line. From your perspective, why is that early clarity on things like the NVHR so important when it comes to planning a project?

Mandip Bhamra: Yeah. So the number one, you need a realistic budget. So some outfits might say, right, go in at a lower cost and then you start having the add-ons when you have problems on site with all trades. I mean, that happens. But if you have a really realistic estimate right from the beginning, then you can stick to it. And by designing it earlier, you can actually save money. in the design process. So if we got in just for technical design, so just before reaver stage four, we can actually help the architect design it with MVHR in mind. So you're not having extra revisions. So there's a lot of costs that can be saved underlyingly over the time and also not having to squeeze it in and having lowered ceilings that are laid to date. So that does go a long way.

Mayflower Mortgage: So from our side, the earlier these decisions are made, the easier it is for us to structure the finance around it rather than coming in a little bit later on. So the well thought out project makes everything simpler rather than reacting to surprises halfway through the build and trying to, like you said, retrofit from there. From the sort of crest side of things. So blue sky scenario, what is the perfect end to end route for You know, self-build building their own home. trying to go for that eco home standard. Maybe not a hundred percent passive house, but trying to get in that, that sphere. What's that end to end journey look like from your side? Where do you want to come in? How would you want to work with the client? And then how much support do you give going on going forward?

Mandip Bhamra: Okay, so in terms of the not just the MVHR, I'll just give you my take on the whole project. So number one, if you're going to build, you know, you're to spend the money and effort to build and the pain of building your own house, if you're just going to do it to building regs and do a rectangle, just go and buy buy it, buy one from a developer and save yourself the pain, you know. But if you want to go above and beyond and enjoy the building for the long term, it is worth getting it very very airtight. So without having to go for passive certification, insulation is expensive. So a lot of people think, oh, let's put more more insulation in, you we'll have a more airtight building. But if you go for something called PHP modeling, passive house planning package, that's a set of calculations that can tell you how much to insulate by. And you have all the figures to adhere to to get the the actual end result. So that could be worth going for without going for certification. So that's more of a planning thing. Don't have to build a horrendously massive house. Humans don't need 1500 square meter houses for two occupants. Have the house you want, but if budgets are tight, just taking 10, 20 square meters off can make a huge difference to your budget, massive difference. and you can upgrade on the insulation. ⁓ Windows are another thing, so part O, which is overheating, lots of people put lots of glass. So if you've got loads of glazing on a south or a west facing elevation, when you get your SAPs done, you could fail part O. So that's looking at the G values in the glazing and potentially adding cooling. Now you can deliver MVHR through cooling. it's done on a slightly different level to air conditioning. It's done at more of a comfort level. So we normally understand by doing thermal modeling what your cooling requirements require. So getting things like that done right from the beginning, the orientation, the amount of glazing can mitigate a lot of this. deciding what type of heat emitters you want, underfloor heating, ⁓ radiators, heat pumps, if you get all of that included right from the beginning. You can all, you know, things like air source heat pumps, where do you locate them outside? If you are going to have cooling, we normally use an air source heat pump in reverse, so you can double up on that. That can deliver cold air. But yes, ideally, before Reba stage four, we would have done all the design work with the architect. The client's building a sensible build, wants to get reasonably airtight. and first fix, second fix, plant install, commissioning will all happen in sequence over the next six, 12 months normally. When we start a project, we're normally 18 to 20, 24 months till we get on site. So it's a long journey. So we do follow the customer journey, but it's important they're allocating the budgets towards the things that add value. So yeah, I'd say

Mayflower Mortgage: So it's early.

Mandip Bhamra: A good quality size build, fabric first, not excessive glazing. You don't want to build a greenhouse, but also make something that flows well and you can live in and enjoy. I say, I would say forever. I don't like the term forever home, but you know, if you're to live in a house for 20 to 25 years, that is very, very long term. So ideally you don't want to have to start changing units or anything within that time. You want to be able to enjoy your investment.

Mayflower Mortgage: Yeah, if you're building your dream home, then build it right, plan it right, and reap the rewards of it all working properly for the long term.

Mandip Bhamra: Exactly, exactly. yeah for the future ⁓ climate as well you know yeah

Mayflower Mortgage: Yep. Well, today it's bucketing it down. So bring on the global warming. So do a quick sort of myth busting round of that's all right. And just so fire some things at you and get your view. So NVHR is only for passive house homes. What do you say to that one?

Mandip Bhamra: Yeah, that's great. ⁓ it's not, I mean, some people assume they are and the word passive is, is the term misused quite a lot. ⁓ so any home can have NVHR. ⁓ obviously if you're an old leaky building, you're still going to take damp, stale air out of the building and also moisture. So you want to pause the conversation and mildew, but I would say on a practical level, if you're doing a deep renovation, So insulating, pulling the fabric or doing a new build, it should either be mandatory or very seriously considered because the beauty of having the NVHR to satisfy part F is you don't have to have trickle vents in windows. So why spend a lot of money on your glazing, which will be a lot with what people are building and then drill a hole through it. It doesn't make any sense. So keep the heat in. Yeah.

Mayflower Mortgage: here sort of defeats the point. Second point was up here and you can just ventilate by opening a window. What would you say to that one?

Mandip Bhamra: absolutely you can yeah why not I've got a lot of friends that are farmers and their windows and doors are open 24 7 they're in for their steak and a tea and out from the Arga and that's a lifestyle thing but drawback with that is you lose all your heat so you know it's the German there's a German phrase I can't remember what it is They open their windows and doors every single day for 20 minutes. So you do get all that air change. That's a cultural lifestyle thing in the UK. You wouldn't want to do that in the winter. ⁓

Mayflower Mortgage: So yeah, you're losing the heat and that's where the NVHR comes in. The heat retention, lower costs for heating bills, keeps everything circulating.

Mandip Bhamra: Yes, the heat. it doesn't, by opening a window it's only going to have a proper effect if you've got the wind blowing through right throughout the house to get the full air change so yeah which is not guaranteed

Mayflower Mortgage: And we'll decide on ventilation when we're on site is always the other one.

Mandip Bhamra: ⁓ Yeah, yeah, that's always a tricky one. I mean, but we've basically got to work with what we've got. I've just actually, from the grand design show, I just met a couple of architects and there's a lovely historic building in central London, four stories, the client has just said I want MVHR no matter what. And yeah. I've got to see if we can physically do it now. They've just put eight, they're not pulling all the ceilings down. So yeah, on a practical level, said, you know, that's going to be a measured survey. We don't have full sets of plans. So we have to see where we can put the unit and physically put it in on a new build. Yeah. I mean, if you plasterboarded and you think, ⁓ forgot to put the NVHR in, it's become a retrofit. You can have to pull a few ceilings down and undo the work you've done. So yeah, it costs more and you end up compromising on ducting routes. I the last thing you want is for ducting routes to be trailed around steels and boxed in. It's far from ideal, but sometimes you have to do that. Yeah, exactly.

Mayflower Mortgage: Needs must sometimes. ⁓ And last point, all MVHR systems are basically the same. What would you say to that one?

Mandip Bhamra: back to your cars, would you drive a Dacia? So yeah, it depends on service level. mean, if you're, suppose if you're doing 20, 30 houses, you might not be able to budget for, you know, your top end for longevity. So yeah, it all depends on what you need, what level of filtration you want, because most...

Mayflower Mortgage: Yep.

Mandip Bhamra: most units might only have a G4 filter you can have an F7 as well the airflow droid has two G4 and one F7 so if you've got problems with hay fever or asthma you do want that higher level if you live in certain areas so Fulham you need NOx filters so any built-up area where there's very heavy traffic pollution you need another level of filtration running costs noise levels you know it's all a factor so nothing's like for like unfortunately so it's important to evaluate what functions you want so what kind of monitoring you want and yeah how long do you intend to live in the property and how often do you want to maintain or replace it at the of life

Mayflower Mortgage: Amazing. ⁓ and to wrap up sort of the main content side of things. If listeners just remember three things about sort of this conversation about ventilation, what would they be? What's your top three sort of.

Mandip Bhamra: Yes. Top three, would say, well, speak to us as early as possible. consider the NVHR as part of the fabric. Don't sit as an afterthought, something you have to do, because it really is an investment. does, apart from the health benefits, know, taking away damped, stale air, VOCs, filtrating pollen and particulates, it does actually help the property breathe. and you don't have your problems with mold and build you damp condensation. So that's the first thing so we can design it correctly. The design service secondly is critical so if you're just going to get a 2D model that doesn't show how to get from A to B your installer effectively becomes the designer so you can't guarantee the output. So if you can have comprehensive design service whereby you're basically going to get the system to flow to complement the build and get the achieved results especially with noise levels. Three, you've got to work with someone that you trust you know it's a long relationship from the start to finish so if you do choose for a full turnkey solution It's never like for like from each outfit. So just make sure it's got everything included. Check your exclusions. Because end of the day, it's zero risk to you then if you go for the full turnkey solution. It's all on the company that installs it. So I suppose number four, if you want to know more, come and talk to the Bollywood null building.

Mayflower Mortgage: Perfect, that's a great place to sort of wrap it up. But yeah, a great checklist. Think early, design properly and include it.

Mandip Bhamra: you Yeah. Yeah. Yeah. Right, yeah.

Mayflower Mortgage: Thank you, Mandip. Thank you for coming on and Solar Crest, the part of our, our saver solution with Mayflower as well. So to get in contact, we'll have all your details on the podcast. Visit Solar Crest website or Mayflowers and you can link in from there as well. But we plan the self-build or renovation. A good reminder that performance starts with the fundamentals and decisions like ventilation, although not very sexy, aren't just technical. They do affect the...

Mandip Bhamra: Yeah.

Mayflower Mortgage: whole project overall. So yeah, thank you so much for coming on.

Mandip Bhamra: Thank you, been a pleasure. Thank you. Will do.

Mayflower Mortgage: Cheers, Vendette, and I'll speak to you soon. Cheers.