LnP

What are installers currently doing about fire risks for in-roof installations? This guidance from the Fire Protection Association recommends (para 5.1.3): New rooftop PV installations, including panels and fixing systems, shall not lower the fire performance/classification of the roof. In-roof systems should have the correct fire qualification to satisfy the requirements of the Building Regulations. If installation on a combustible or partly-combustible roof is unavoidable, then a fire resistant covering should be applied. Perhaps sheathing the roof under the panels with cement board rather than OSB sarking?

I was assuming that a laurel would be smaller than this, but that could be an incorrect assumption. Apologies for any confusion. If it does meet these criteria, the next question would be whether a laurel is a tree or rather a bush or a shrub. Maybe speak to your LA arboriculturalist.

The official answer, "All trees with a stem/trunk diameter of 75mm (approximately 3 inches) or more at a height of 1.5m from the ground are protected in a Conservation Area." So no you don't. We're in a conservation area. You should ask your AT what successes he's had dealing with your planners to check he has a track record of success. You mentioned he was up for a fight and was cheap, which might not be the best selection criteria. We have an architect but also engaged a planning consultant and are glad we did.

The company I used was Underground Surveys.

Just came across this and can't let it pass. This is very bad advice. There is no safe lower limit for asbestos exposure. One fibre can make you sick. It causes a range of illnesses including chronic respiratory diseases such as asbestosis (fibrosis of the lungs), and various cancers. The worst one is mesothelioma. None of them are curable, it's a one way ticket and it only takes one fibre. 5,000 people die every year in the UK from asbestos related diseases. It used to be said that some forms are worse than others - blue, brown chrysotile whatever. That's not the case anymore. All six forms have been found to cause cancer in humans. What does vary though is the precautions you should take, depending on the material. Asbestos cement is easier to deal with than insulation because if it's in good condition, it doesn't release the fibres. There is plenty of guidance out there on what to do about it if you think you might have asbestos and plenty of companies who can deal with it. A good place to start is the HSE, link here. You can also get cheap DIY test kits from Amazon to get a sample tested - follow their advice on how to safely take the sample. I know that happily the OP'S problem was sorted, but couldn't let this go without comment.

@Gus Potter Thanks for your thoughtful reply. Thinking about this point though... is it possible the fire prevention measures could make TF too expensive?. Would it be that difficult to get to a Category C1 Fire spread resistant frame? Maybe just replace the OSB sheathing on the wall facing the neighbours with a e.g. cement board or similar? Even getting to a Category C2, which means you don't need any separation, just means not cutting out the window apertures in the sheathing until the external cladding is up. Obviously depends on whether the cement board has the necessary structural strength. If you've thought about this at the design stage, perhaps the extra cost is just the difference in price between the OSB and the cement board?

Actually not sure that's quite correct. Maybe we should say it's expensive gas and even more expensive electricity! Expensive electricity is not just a problem for heat pump implementation. Jim Ratcliffe, CEO of INEOS (and these days Manchester United shareholder) is blaming high electricity prices on the demise of the UK chemical industry. Mind you, he could have also have mentioned Brexit, which is just as much of a problem, but that would have been embarrassing for him because at the time, he said it was a good idea. More recently he's said Brexit hadn't worked out as he'd expected. What a surprise.

It's a different skill set. Lots of people use architects to provide planning advice and I'm sure it works out fine, but it's not core to their business. You can even do it yourself if you're prepared to take the time to read lots and learn it and if your situation is straightforward. But there are lots of wrinkles and traps - CIL, BNG, heat pumps, bat surveys etc and there's new stuff coming along all the time. Some of it is not written in the guidance and very subjective and based on precedent. Our project is in two parts. The first part was to renovate a Victorian coach house in the garden, for which we needed to get planning permission. It took so long to be determined and we wanted to get started that our planning consultant advised we could take the risk and start. We were 2/3 complete by the time we got the planning permission. I wouldn't have done that without professional advice. The second part of our project is proving to be not straightforward and I'm glad to have his support. Wherever you go, you'll have to pay for it so my preference was to engage an expert. I found our guy through the RTPI web site. We engaged him before we engaged an architect because we needed to sort out planning issues first. He was previously head of development and control at our local authority so he does know his way around.

Good advice. We're using a planning consultant and consider it money well spent. You can find one via the RTPI web site.

The Electrification of Heat Project looked at this. They concluded, "There is no property type or architectural era that is unsuitable for a heat pump ...From Victorian mid-terraces to pre-WWII semis and a 1960s block of flats – the project has proven that heat pumps can be successfully installed in homes from every style and era". Although it's probably true to say that the less well insulated the house is, the worse the economics will be. It probably depends on your definition of suitable.

@Gus Potter since it's timber frame, what are your thoughts about needing to have the structure assessed against the STA Design guide to separating distances during construction?

I lived in Canada for many years, owned houses and had work done. It was all tapered edge plaster board and taped joints. Providing the structure you're fixing the boards to is straight, it's cheaper to do than plastering and once it's painted, you'll never know the difference. I built stud walls and taped the joints myself and you'd never have known it was done by an amateur. That would not have been the case if I'd attempted plastering! Drywall compound in Canada, which you use for the taped joints, is a mud which doesn't chemically set. Is that the same here? After it's dried, if you're not happy with the finish you can sand it, though the pros would never need to sand! You use three widths of "knife" to apply it in three coats. The first coat with the narrowest blade is the one you put the tape in. I'm wondering why traditional plastering is still the norm here ....

That's a nice story. Maybe if it had been a Michelin blimp the spill would have been met with a Gallic shrug. But the hazardous properties of the Avgas which the airport fire brigade would have been worried about, would have been its vapour pressure (the extent to which it could be the source of a flammable gas cloud) and its flash point. The Buncefield explosion incident in 2005 was caused by a release of gasoline/petrol from an overflowing storage tank, albeit on a much larger scale than your 80- 100 litres. Avgas is a gasoline/petrol formulation. Unless there are embers falling out, what causes combustible building materials like wood panelling behind wood burning stoves to catch fire, isn't the release of flammable vapours. It's autoignition. Regarding Markocosic's towel, maybe it depends how much after shave he's using ...🙂.

It's not the flash point you you have to think about, it's the autoignition temperature. They're not the same. Flash point is the temperature you have to heat something to so that when you hold a naked flame over it, the vapours coming off it will ignite. As you raise the temperature, the concentration of the vapours in air increases until it gets to the lower flammable limit and a flame will ignite them. Autoignition is the temperature you have to heat something to so that it ignites without the presence of a naked flame. Not being pedantic, just want to highlight that it wasn't a naked flame which caused markocosic's towel to catch fire. It just got too hot.

On the subject of wood burning stoves and health and safety, be sure to follow the guidance on separation from combustible materials. I have a relative in Canada whose house burnt down because his stove was too close to some wood panelling. The radiant heat from the stove raised the temperature of the wood above its autoignition temperature and it ignited. Autoignition - you don't need a spark or a flame, just get it hot enough and it will burst into flames, like a chip pan fire.

SMRs are not going to be commercially available for a long time yet. There are numerous designs in development but only one has been licensed for commercial operation (see earlier posts in this thread). That design estimates an electricity cost of $0.089 /kWh but on past experience with nuclear, you can be sure that the price will rise a lot, and not just for inflation. So more expensive than renewables. None have been built. For sure they will be part of the long term solution but not in time for net zero 2050. The risk though is that people use the hope of non-available technologies like SMRs to delay getting on with implementing the available ones like insulating our homes and electrification of heating and transportation. Yes there are challenges with electrification, like grid capacity, but we just need to get on and do it.

I guess you're talking about when the wind isn’t blowing and the sun isn't shining. Nuclear isn’t the answer. Flexible generation is what's needed to balance renewables; nuclear is inflexible. We could doubtless build it to be more flexible, but then it would get even more expensive, both due to the extra engineering required and running at a lower capacity factor. If we asked it to run like we are now running our gas CCGT plants (35-40% capacity factor), it would cost around double the current unit cost. Exactly how much that is, nobody knows of course. Hinkley C strike price is £137/MWh in today’s money, but it’s nearly 100% over budget, so perhaps the real price is closer to £200/MWh at its design capacity factor. Operating like a CCGT could make that power £400/MWh. That's 40 pence/kWh vs the current Ofgem energy price cap of 25 pence/kWh. The jury is still out on what technologies will provide the required resilience. I've seen articles suggesting that short duration supply/demand imbalance will be managed, as batteries become cheaper and more ubiquitous, by a mix of EV smart charging and V2X. Longer "Dunkelflauten" might be managed by gas back-up or through extensive interconnection (even transatlantic) to avoid correlated weather events, or biomethane and hydrogen to power. Nuclear is unfortunately swimming against this tide. How this eventually looks will depend on finding the right mix of market and regulatory mechanisms. Let's hope our regulators are up to the task and resilient to lobbying. Credits: Most of the above is taken (even copied!) from LinkedIn articles by Rachel Lee.

@SteamyTea is unfortunately right about nuclear. I grew up at the Atomic Energy Research Establishment at Harwell immersed in the hopes that surrounded it. But it has just proven to be too expensive and takes too long to build. We don't have the time or the money. SMRs might eventually help. There are numerous designs in development, but as far as I know, there are currently no licensed commercial designs anywhere in the world, let alone any built. Regarding Hinckley C, I'm reminded of a headline in the Economist, "What's the Hinckley point?". Unfortunately, the hope of a nuclear solution has the risk of being a distraction.

I don't know where the weather station is that the software in my boiler gets its temperature data from, but if it's a degree or two out, it won't matter. There are a host of other factors which a simple WC heat curve won't take into account, not least of which is that the "curve" in my boiler software is a straight line while the relationship between heat loss and flow temperature is non linear.

It's in a Victorian coach house in the garden which we refurbished as guest accommodation. Solid walls lined with insulated plasterboard. We don't use it very often so really can't comment on comfort levels except to say that the people who've used it said they were comfortable. It has radiators. I can select the Heat Curve parameters via the app. Right now, there's nobody there and I have it set on Away mode which has a room target of 10 degC. Outside is -2 degC and the flow temp it's chosen is 23 degC. If I turn off the Away mode it's targeting 20 degC room temp and it selects a flow temperature of 53 degC. Pretty straightforward and easy to make changes. It seems to work fine, though as I said, we don't have a lot of experience with it.

My Worcester Bosch boiler is connected to the wifi and gets its outside air temp WC data from the internet. No thermostat outdoors. And the EasyControl app allows me to control it remotely.

It doesn't and MCS didn't say that. They highlight the problem with Building Regs compliance. I agree. I don't read it as buck passing. Looks to me like MCS are trying to sort the problem. Still trying to figure out what this means for a new installation.

Indeed, but GSE say that is a list of panels they have tested and received positive, indicative test reports from the Warrington Fire certified laboratory. They go on to say that while solar modules can still be tested, the challenge lies in obtaining classification under BS EN 13501-5 BROOF (T4). So I'm confused. Will BC sign off roof integrated roof PV panels without the classification?

It seems to go farther than that: "where solar products form a roof covering (i.e. roof-integrated) a fire classification is required so that compliance with Building Regulations can be demonstrated (specifically Regulation B4: External fire spread). Any new products brought to market are currently unable to obtain a fire classification and therefore cannot be integrated into roofs in compliance with the Building Regulations. This also prevents them gaining MCS certification." So Building Control will in future not be signing off roof integrated PV panels until fire certification is sorted out. Seems unbelievable? @SteamyTea the 4 on which list. I missed that.

Link here to MCS Update. And I got an email from GSE. Not sure if this will work but it says it can be viewed in a browser, here. Any thoughts on what this means?