Leaderboard

>Why don’t large commercial companies have PV ands battery storage ? Maybe not here, but the EU is working on making PV a legal obligation: https://ec.europa.eu/commission/presscorner/detail/en/ip_22_3131 A Solar Rooftop Initiative with a phased-in legal obligation to install solar panels on new public and commercial buildings and new residential buildings.

I think the large pipes are a hangback from the gravity systems with a tank in the loft.

Why isn't it? not sexy enough? Wouldn't make money for cronies? Simply zero rate all insulation tomorrow and diy would increase

You do not want to upsize the hot water pipe. You’ll massively increase the delay in getting hot water out of basin / sink taps. 👎

Not sure why you are not just using the heat loss calculations in the boffins corner, it lets you set the ACH and MVHR efficiency. It free easy to use and pretty good representation of what to expect from your house.

If the MVHR unit is 80% efficient (optimistic in reality) that means 20% is not recovered. Room by room or whole house probably does not make much difference, but the Building Regs specify flow rates. Just convert from litres per second to kWh per day.

Try 20% of the value.

There is no such thing as a standard heat loss per square metre. It will be individual to each building depending on insulation levels and air tightness. Once you get to a certain level of insulation, then ventilation heat loss starts to dominate, and that is really where MVHR works best. At this stage in a new build you should be striving for maximum insulation, detailed well, and very good air tightness, and then mvhr will get you a low energy house.

It does get easier from here on This time and last I’ve had a torrid time digging out In my humble opinion a 5 tone machine isn’t man enough in tough ground I ended up hiring a dozer to move all the spoil 500 per day for the machine plus 300 per day for the fuel Groundwork’s is the only unknown part of your build The rest should be plain sailing

Bloody hell. At least you’ve started! I’d be triple checking everything is in the right place.

If you have hit hard ground that has the digger "digger shaking like a shittin' dog" do you really have to scrape it any deeper?

Why?, my bath, kitchen tap and showers are all on 15mm with basins and toilets on 10mm, very adequate and quick to get hot water, 22mm is old standard (IMO).

That compactor is even cheaper now - 199 + delivery Scheppach 6.5HP Petrol Compactor - ALDI UK

Everyone gave lots of help last year on this, you just wouldn’t listen to sound technical advice from multiple different sources.

FWIW, I’m on a TF house atm, with 300mm glulams and I got permission for pre determined / agreed location etc 96mm holes. Can be up to a 1/3 of the depth dependant on thickness of wood.

Structural engineers can help you decide where to drill that number of holes. You should be fine, don’t go to the expense and ugliness of boxing in etc 👎. You can stop the insulation ( if it’s actually required ) either side of the joist to make the holes smaller. What is the 22mm feeding? Not hot water?

Mine was very similar, dead easy to apply with a brush, did approx 90 sq m in half a day, can’t see it when finished, rain runs off it like glass 👍

As above the tapered roof design Co are trying to get the 'balance' of insulation correct to avoid condensation issues. This can be modeled quite well using BS EN 13788 without resorting to WUFI. The are specific design issues with warm flat roofs that cover the install of the AVCL - most manufs will want this fully supported on the structural deck/below the insulation. See MIs and BS 6229.

Just resubmit and leave the entrance as existing. You can later install gates without seeking further consent. Highways can be sticklers for these things but their only point of power will be to object to the application and they cannot do this if the access is unchanged.

There are evaporation losses from wet walls, these can be quite high, especially at night. The latent heat of vaporisation is 2257 kJ.kg-1.

True. Using the data over the year 2020 we had an average temperature of 12.1 centergrade here. The average temperature in the home was 21C (19 for about 8 hours over night and 22 the rest of the day. We would require about 1157 Watts to heat up the same amount of air taken directly from outside, as apposed to, the 231 Watts of heating required and 32 Watts to run the MVHR. So a saving of about 926 Watts an hour. 926 Watts by 24 hours by 365 days is 8111 kWh a year! Note: In this example both ways of calculating do not take into account heat produced in the building, from people, heat all electrical appliances or solar gain. Estimating these brings the difference between air inside to air outside to only about 4.1C and the saving down to about 2000kWh a year for us. FYI our home is about 105m2 on plan! In my humble opinion, you have to have some really really poor MVHR design for the running of the MVHR to cost more than the saving on heating.

Brilliant idea, I think our gov should give the £5K they offered fir installing ASHP,s should be given towards insulation instead (don’t get me wrong I have an ASHP and it’s good fir me). But insulation will reduce ANY type of fuel use and lasts forever.

That sounds counter intuitive to me! I have a west facing wall and believe the wind chill will lower the temperature of that wall which will “suck” more heat through the insulation , hope to be proved wrong!

If you are considering drilling the joists then presumably its not been plasterboarded yet? Could you fit counter battens at 90 degrees to the joists to form a void below them to run the pipes in? The battens would need to be the same depth as the diameter of the insulated pipe. The ceiling would be the same amount lower.

@Russell griffiths yes, 195mm deep timbers 4 aside, as well as two RSJs perpendicular to each other. Panels sit in-between and are insulated. As for complicated buildup - that was the vented cold roof design by the architect which requires over fascia vents on the internal side of the parapet, along the existing house and even along some sides of the roof lights. Those roofing details strike me as being prone to failure and a potential source of water ingress with driving rain. Not to mention potentially ineffective at venting the roof. SIPs are normally considered a cold roof construction. As far as "needing" the 120mm of PIR - that's what the tapered insulation providers have said is the minimum to avoid interstitial condensation. They are basically shifting the dew point as far away from the SIPs structure as possible.

(I don't see the screen shot?) This sounds very similar to the standard MCS heat loss calculator template. We used the "Cat C" columns below, which assume 0.5 of 1.5 ach with a special note about extract ventilation. The issue with their spreadsheet is less the specific ACH used but the fact they have no calculation for heat recovery of any sort. The net result was it overestimated our heatlosses by 100% vs PHPP.

I think I would prefer “proper” tarmac , see if a local company would do it with a leftover from a big job nearby.

@Russell griffiths think the build up is sips between joists or rafters rather than on the top. We erected the Sips “Oyster House” at the ideal home ex many years ago and that was all done with sips infills in a glulam grid structure

Is part of the problem that a house leaks air when there is no forced ventilation, then, adding forced ventilation just adds to the losses, even if it reclaims an optimistic 80% of the energy in the expelled air. So let us assume that at 5 ACH and a delta T of 15°C. 1 tonne of air has 15 MJ of energy, that is 4.2 kWh, every hour. Add on another 0.5 ACH for forced ventilation, that is 4.62 kWh every hour. Even if an MVHR system can reclaim 80%, that is 4.284 kWh every hour. Change the natural looses ACH figure to 1, and that becomes 0.84 kWh every hour, add on the 0.084 kWh for the MVHR, then 0.924, call it 1 kWh, or 24 kWh a day. Get the house airtight, more airtight than you can imagine or you are, at current gas rates, throwing away 15 quid a day.

A badly designed MVHR system can have a negative effect on the SAP outputs - if the cost (money or energy) of running the fan is greater than the energy saved.

What a crock of ......t! I don't know where to begin! Sap man may be right that SAP calcs are about as good as EPC calculations and assumptions (don't get me started about EPC's) but as efficient as opening a window? That's utter bollix. Hi @ruggers In my world, when you open a window to let air in you let other air out, Our home tends not to expand like a balloon. In doing so the temperature of the air going out is replaced with the temperature of the air coming in. So when we open a window on a very cold winter's day, the outside air at, say, 5C replaces the warm air in our home. However on the same day the air supply from outside via our MVHR is usually around 20C. This sounds like a small thing but when the maths is done over 24 hours and 365 day a year its a lot! If the outside temperature at our home is -1C we will use about half a kWh replacing the temprature of the air using the MVHR in an hour. If instead we opened windows and replaced the air in the house at the same rate as the MVHR we would use about 2.5kWh an hour. Our MVHR uses 25 to 33 Watts an hour. I am completely satisfied that using an MVHR helps to keep our home at a more stable temperature (resisting both hot and cold outside temperatures) and saves us energy and saves us money. Its the gift that keeps on giving... Good luck with your project M

I know nothing about tarmac, but.

It's a mix of sand, cement and 10mm aggregate. https://www.wickes.co.uk/Blue-Circle-Multi-Purpose-Ready-To-Use-Concrete---20kg/p/133770

Silly SAP. It's very expensive and inefficient to open the windows in winter, as doing so lets all your expensively generated heat out the building. (Likewise in a summer heatwave opening windows allows all the expensively cooled air out). This was the first thing that got me looking into MVHR: I hate the wastage of open windows in winter, my wife hates the humidity and damp of closed windows.

MVHR are not 100% efficient so do reduce things, they are just "less bad" then trickle vents and extractor fans.

Which software are you using? MVHR should improve your heatloss as it warms the incoming air from the heat embodied in the outgoing air.

Save your SE money and pay a brickie a days wages to repoint it!

They may be asking for more drawings to justify exceeding the target decision time. Just give them the drawing requested, a traffic survey is unlikely to be taken into consideration.

ewistore.co.uk P.S. thanks for the reminder that i'd actually done this, forgot to put it up

From the latest photos it looks clear to me that it's just a failure of the pointing. All bricks look to be in reasonable alignment apart from one corner brick on the slant but I expect it was laid like that to begin with.

I just had a look. You're right, it makes no difference for the actual heat loss. Thicker insulation will make a smaller psi number for the external thermal bridge but this is all soaked up in the calculations anyway as you'll have more external area with a thicker build up. Our EPS Graphite was 0.031 vs 0.022 for PIR ( if you believe them!) It was about 2/3 of the final cost for us to use EPS vs PIR. Obviously that may differ depending on where and when you build.

It's quite interesting to see how vested interests are using this emergency (having been escalated from its previous crisis status). The Ch Exec of Scottish Power (seemingly supported by the bulk of the industry in the UK) , has proposed freezing prices and the govt loaning energy companies the excess required to buy energy at whatever the market price is over the next two years, with that money being paid back by bill payers over the next 20 years - basically the governments original £400 help proposal on steroids. What he neglects to mention is that it neatly takes the risk away for the industry in terms of non payment and potentially cutting people off, and will allow their generation arms to continue making money hand over fist where that generation is fixed cost. Easy to see that the government will be seduced by this approach, neatly kicks the can down the road and they can present it as keeping bills down, as a loan to industry rather than public debt and to keep the green transition alive. Telling people to use less, turn down the thermostat, wear a jumper etc simply is not a political option for the government, even though it is what's actually needed.

https://www.centrica.com/investors/results-centre/2022-interim-results/ British Gas also produce gas. The profits of their residential distribution business almost halved in the first half of the year to 90 odd million. The profits of their gas production business on the other hand went up more than 10 fold to over 900million. Basically non Russian owners of energy assets are making out like bandits as they can sell all the gas they can produce at massively inflated prices. The media has absolutely no interest in reporting things calmly and sensibly so just lets people be confused by the thought that their gas supplier, British Gas, is making lots of money. It’s not even called British Gas any more, the company is called Centrica, BG is just their energy supply brand. If BG is doing well then all energy suppliers must be doing well. Energy suppliers are of course majorly hurting, it is energy producers that are doing well. Norway must be making an absolute fortune. We can’t charge a windfall tax on Norway! One possible solution would be to exert political pressure on countries like Norway to sell gas at below the market price. They won’t like it but it is totally immoral of them to be taking advantage of a situation caused by a war. Now I’m all for free markets, but within reason. They could be selling gas for twice the previous price and still making a fortune. They need to be able to do this to offset times when prices are low. No one offered to pay extra when prices collapsed due to COVID. But prices are not symmetrical, they cannot go lower than zero but can go up infinitely in theory. This ceased to be a normal market when Russia invaded Ukraine and restricted supply. Windfall taxes are a roundabout way of taking away excess profits but they cannot totally fix things as net importers of gas cannot tax net exporters.

I would go into the link Nick gave you. You need to know your floor area and perimeter and floor buildup. Then just play with the calculation

These are some really good questions. Yes you'll read a lot about trees, their roots and also some horror stories. In some ways.. I think that there may be two issues here. One is that your neighbour has planted a tree that could overshaddow say your garden when it grows without thinking of the consequences. Folk do this.. they like a kind of tree and don't realise how it can impact on their neighbours. Also the hedge.. For you, your first step maybe is to maybe think about how simplistically trees grow, large shrubs are different a bit . Trees that grow big (tall) need some deep roots, they stop them blowing over in the wind. They have other roots that gather nutrients and water and these are close to the surface and spread a long way. They follow the path where they can expand and are close to the surface.. hence why you see these roots under your slabs.. you may have a nice bit of sand bed that encourages the roots to spread, there will also be some very fine roots. The funny thing is that as you have slabs the roots have no competition from weeds and other plants.. you can't blame the tree for taking advantage of this. These secondary and tertiary roots seek out nutriants. To get a handle on this identify the type of tree. Decide if you like it, could be a say a cherry / hornbeam that flowers and looks great / stunning! Could add to you enjoyment of your garden even if not in your ground. If you try and understand how the tree grows, the kind of soil you have and where you live ( Kent or Shetland diiferent rainfall) then you may be in a much better place to manage not just the tree but your neighbours! Now the laurels are a bit different! They are not that fast gowing but they are sturdy! I think. Again though your best approach is to start with understanding the ground and one tree. Engage with your neighbours. You could say.. what do we need these trees for. Do you want privacy? But I too want privacy.. but don't want my house damaged! I may come over as a bit soft here but what you are doing is to establish the facts and groundwork should this escalate into a dispute that you need to involve say an SE. It could be a case of stick and carrot here. The best way is to use persuasion. if that does not work then further persuasion with a hint that you may hold a big stick!

I live a pretty basic lifestyle (by choice) and as a self employed person I only turn over about £20-22k a year my outgoings are fairly high as I support 2 kids 50% of the time as well as feeding and housing 2 other adults for 6 month of the year, I run an Airbnb so have all the overheads associated with this. Most years I can save about 4-5k which goes mostly on building materials and repairs and maintenance. I am working towards getting another building finished so that I can rent it out and boost my income by 10-15k but it’s still a year or two from being done. In the past it’s all gone well but this year my bank balance is pretty thread bare……. The general price rises have squeezed my margins to nothing and I am eating into what little savings I have, it’s pretty unsettling with the electric price increases that may come as between the various buildings I have and the Airbnb my current electric cost is £300 per month. I have upgraded the insulation in my house walls and ceiling which has made a significant difference to comfort but still need to replace the 4 windows which are totally shite…. No insulation in the floor and not easily done at this time. The immersion is virtually never put on. Not quite sure where I will make the financial cuts to cover the ever increasing cost of living but I am sure I will come up with something 😁

All over central England we have been build massive warehouses in recent years. None that I can see have pv on the roof. Some are millions of square feet. Then up the road there are PV farms being built on agricultural land. Madness.

If your MVHR fails on the coldest day your heat demand would go down not up. You are in a nearly airtight house otherwise you wouldn't have MVHR. Think logically, MVHR provides the ventilation, it recovers heat from the outgoing air and transfers to incoming air with some losses. If there is no outgoing or incoming air, because your MVHR has failed, then there is no losses, so heat demand reduces. Your installer is less than dim, possibly has no real idea what an airtight house is, or what the MVHR does

To be blunt, you have three choices. 1) find the gap in your £1M budget and keep your shoes clean. 2) exit your comfort zone and get involved in the build 3) quit your project. We ticked all the same boxes as you - zero experience, zero DIY talent, and we also had busy jobs and small kids. In Berkshire so same neck of woods cost wise. We were also looking at unaffordable costs for our 400m2 home but managed to get it in for £1500/m2 back in 2016. Appreciate that there has been a lot of inflation since but £2k-2.5k/m2 should still be very doable. £3500 /m2 is a very premium price - no doubt you could spend that but it feels very top end. Using a single main contractor is always the most expensive route as they will price contingency and management overhead into their costs. However as a self builder, you don't need to get your hands dirty, you just need to organise trades, contracts and occasionally materials and preferably live on site (which will save you £££ on rent especially in the SE). A laptop and phone plus a tape measure will be your main tools. When you get planning, the decision on what to build your house from is still an open question. Planners only care about the external appearance. So, assuming you're successful, you now need to spend some time evaluating different build methods. Get budgetary quotes from builders assuming brick & block. Shop your planning drawings around timber frame companies to get frame costs. Talk to ICF firms for their perspective. You don't need detailed drawings to do this (indeed, having such drawings assumes you've already made that decision). Everything aside from the frame will be the same - roofing, windows, exterior cladding, internal fix & finish, landscaping etc. Timber frames lend themselves to self project managing as many of the structural issues are addressed in the one package - sometimes even foundation systems. We went that route (getting a separate contractor to demolish the existing and build a basement). From there on it was straightforward to source trades to complete each stage and get ahead of the next few steps. Once we'd made the TF decision, we got a QS to do a detailed estimate (still no drawings at this stage, in fact we never bothered with more drawings from architect post planning as the TF firm did all we needed). We used this estimate to sense check quotes and look for savings. N.B. You've not mentioned whether your plot is greenfield and needs services, access etc or if you're doing a demolition.

I was surprised that our sap guy said MVR had a detrimental effect on the sap He said while it’s cheap to run and efficient So is opening a window