I have just moved into a new home (1928 3-bed semi), and it was identified in the survey that the roof needs major repairs (possibly full replacement). I was wondering if anyone has any advice of things I could do to improve energy efficiency while getting the roof repaired, e.g. removing chimney stacks, improving airtightness, adding insulation etc.

According to the RICS surveyor: " The main issue relates to the roof coverings. They are old (some 90 years I would estimate) and at the end of their useful life expectancy. The photographs give some idea of condition. Patch repairs have been carried out externally in the past. Daylight can be seen in a few places from within the roof void. There is no underfelt. You will need to budget for new coverings, pre-treated battens and vapour-permeable felt".

The survey also suggested it is quite likely that there may have been damp penetration problems with the chimneys, so I was considering the possibility of removing the stacks. In regards to loft insulation, the surveyor said "Some insulation is present within the roof void although this is considered inadequate having regard to current standards. A minimum thickness of 270mm of fibreglass quilt or a similar standard of insulating material should be provided throughout, ensuring that any essential ventilation openings are not obstructed"

The EPC rating is currently band E with potential for band B. The property is my primary residence and my main goal is to reduce energy costs and my carbon footprint.

Posted By: billyb_1234I was wondering if anyone has any advice of things I could do to improve energy efficiency while getting the roof repaired, e.g. removing chimney stacks, improving airtightness, adding insulation etc.

All of those will help energy efficiency. If you improve airtightness, remember to improve ventilation at the same time. If you have unused chimneys then it may be an opportunity to fit MVHR.

Our survey said something like that when we moved in. We took the view that, as the roof wasn't leaking yet after ~100 years, it could wait a bit longer, we just replaced missing slates and topped up the loft insulation. It was still in the same condition when we sold up 15 years later, and that time the surveyor had no complaints about it, so maybe it will last another century.

Possibly the original surveyors were unsure about historical roof constructions (without felt, hence copiously ventilated, hence well preserved), so they covered themselves in their report.

I know nothing about EPC ratings but fail to understand what you would have to do to a 1928 house to get a B rating. My 2012 house, triple glazed with 180mm of insulation and very well sealed, only achieved a C (and that was mainly because I had installed halogen lights, now replaced with LED)

Posted By: RexMy 2012 house, triple glazed with 18cms of insulation and very well sealed, only achieved a C

Our barn conversion, completed last year, (original building dates from approximately 1800) achieved a B.
It would need PV or a wind turbine to achieve an A.

Posted By: Dominic CooneyIt would need PV or a wind turbine to achieve an A.

My certified PH was only given a C, even with PV.

The EPC rating bands are set on the energy cost in £ per m² per year, the band boundaries are in the back of SAP. I think they may still use 2012 fuel prices as rdSAP10 has still not been published.

To get a good EPC band, heat your house with a coal stove (coal was cheap in 2012) whilst fitting lots of PV and selling the electricity to export (was good income in 2012).

rdSAP uses default U values based on the building regs that were in force at the time of the (re)building, so a barn conversion that was approved after 2012 will score better than a newbuild house approved before then.

Edit: EPCs only last 10 years, so a rating issued in 2012 will no longer be valid.

Our 1850ish house had a 'C' rating when we bought it, because the assessor had entered the floor area in square feet instead of square metres.

The previous owner, the assessor, the estate agent, solicitors and the prospective buyers all didn't think to question this, or else didn't care.

According to

"Window areas are estimated by the age of the property and the floor area.

"U-values are estimated as well, this is the rate of heat loss through the windows, walls, floors and roof of a dwelling. The software assumes U-values for different constructions based on the building techniques and materials available during different age bands. It is possible to overwrite these values."

...

"Acceptable documentary evidence includes , but is not limited to, certificates, warranties, guarantees, building control sign-off from a homeowner or tenant, or official letters from the applicable Registered Social Landlord (RSL). The assessor must be confident, and able to demonstrate that any documentation relates to the actual property being assessed and that there is no physical evidence to the contrary."

There's a hundred more pages that I haven't read. Lists of photos that must be submitted etc.

Posted By: Peter_in_Hungary

Posted By: billyb_1234According to the RICS surveyor: " The main issue relates to the roof coverings. They are old (some 90 years I would estimate) and at the end of their useful life expectancy. The photographs give some idea of condition.

Wot photos ??

Do you want to replace the roof entirely or replace like with like replacing as needed keeping as many of the original timbers as possible ? Talk the your roofer of choice as there may not be much difference in price - on the other hand significant savings may be made.

If you are replacing the roof coverings (a good catch-all phrase that says nothing about what you have) what have you got and what do you want ? (any restrictions from AONBs, planning etc.). Recently I have replaced a couple of roofs and I have gone for large format tiles (interlocking on all 4 edges) as the price /m2 is the same as tradition size but they are quicker to lay and use less tile battens so have reduced costs. The projection of the attic fire wall above the tile level or not may determine tile type but there are solutions of flashing that can be used to over come tile differences - again your roofer can advise.

What the surveyor said about insulation is correct - a minimum of 270mm etc.

As for chimneys I would remove any unwanted chimneys down to ceiling level and insulate over.

If you are thinking about PV then when the scaffold for the roofing is up then this is a good time to install PV if the budget goes that far at the same time. (unlike here scaffolding will probably be put up for a new roof - but ask). Also think about integrated PV i.e. built in to the roof in place of roof tiles, do the costings.

Photos attached.

I don't particularly have a preference between replacing entirely or replacing as needed, if prices are similar then I would probably opt for replacing as needed as it would create less waste.

There aren't any restrictions in terms of planning and I have no short term plans for the attic (eventually I might want to do a loft conversion but that would be 5+ years away if I'm still living here).

I was originally considering PV for the roof but cannot afford it unless the roof does not need full repair and ends up being much cheaper than anticipated. I have also seen some opinions that PV pricing should drop within a few years and efficiency should improve, which would offset the cost savings from only having scaffolding up once. Also the roof is East-West-North facing (the south side of the roof is part of the house next door) which is not ideal for solar.

Posted By: billyb_1234What kind of things could I do to improve airtightness? Also I would not be able to afford an MVHR system for a few years so would it be best to avoid improving airtightness until then or are there other ways to improve ventilation in the meantime?

Airtightness means having an airtight layer everywhere around the thermal envelope. That tends to come down to all the surfaces (roof, walls, floor, doors & windows, chimney) and all the connections between the surfaces. For example if you have a solid floor then it's probably airtight while a suspended floor probably needs a membrane. A plastered wall is largely airtight (apart from between floors and any cracks) but bare walls aren't and neither is dot and dabbed plasterboard with a skim. Roof/ceiling generally needs a membrane. Connections between walls and floor/roof/doors/windows need some flexible airtight connection that will stay airtight over time. It can all be done over time but it's best to make a plan at the start so you know what needs doing.

Mechanical ventilation is generally the best/eaiest way to guarantee a good result but you can get a good result by religiously opening windows every day. Permanently running fans is another alternative. Heat recovery ventilation ultimately/eventually saves money on heating.

Insulating the loft looks to be a priority. Don't forget to insulate over (not under) the water tank as well. And put an airtightness membrane under the insulation.

The roof doesn't look too bad to my untutored eye. Others may see more. Are there any parts that are particularly bad?

Don't power hose the roof. Seen this done round here and it just takes the surface off the tiles and makes them porous.

Agree with Peter. I'd add, check for air gaps into the loft and seal with squirty foam before insulating. Put in cross joists so you can raise the decking and put thicker insulation down.

I would not be reroofing it if it was mine. I would investigate what is behind the bit of black dpc. Timbers look to in great condition

Posted By: Peter_in_HungaryFrom the look of the roof from the photos your roof looks to be in good order. The tiles look to be all around interlocking - good news - and the timbers appear to be in good nick. Unless you have some leaks I would leave the thing alone. If you eventually need to do something drastic with it there will be difficulty in doing much without the neighbour. PV will be difficult because there is not much flat area and the chimneys will shade.

The attic needs insulating and the boarding will have to be taken up unless you can guarantee there will be no drafts from the eaves under the boards that will negate any insulation you put there. Insulate up and over the water tanks to get them inside the heated envelop.

The house looks to be cavity wall, if so do you have cavity wall insulation. What is the ground floor, solid or suspended? Either way insulation should be considered.

The windows look to be UPVC if so are the rubber seals in good nick and the glazing units OK. If yes to both then IMO not cost effective to improve.

Bathroom ventilation is important and a decent powered vent (with RH control) is better than relying on a window.

The house is cavity wall but not insulated. I am looking into this and trying to work out which type is best as each type have their pros and cons. Blown rockwool looks best in terms of environmental impact of the material, however I have read that it can wick up moisture easily and become very inefficient. This is also a problem because the state of the brickwork on the outside of the house isn't great - lots of cracked bricks and damaged mortar, which I'm guessing is a risk for the cavity insulation.

I believe the floors are suspended, and I was planning to insulate and add wet UFH at some point, but probably longer term as I might knock through the kitchen into the dining room downstairs in a few years, so there would be no point doing downstairs floors now.

In terms of Windows they are uPVC double glazed but according to the surveyor they're not in the best condition:

Two painted timber single glazed windows have been retained to the right hand side. Otherwise, windows are of PVCu specification incorporating sealed unit double glazing. The double glazing installation is clearly old. The double glazed units themselves are “beaded externally”. This could be a potential security risk unless “glass locks” have been installed. (Unconfirmed, since the beading was not removed. Glazing was generally “dirty”. A colour-matched flexible mastic should be maintained at the gap between window (and door) frames and adjoining walls to prevent rainwater penetration. Shrinkage/deterioration has generally occurred and replacements will be needed.

There are also two timber framed single glazed windows in the kitchen, which ideally I would replace with double glazing but I'm hesitant to do anything soon, as I will be making changes in a few years when I do the kitchen/diner. I know secondary glazing may be a temporary option though.

In terms of bathroom ventilation, there is currently no extractor fan so this is something I was considering. However if I plan to do MVHR, I assume this would become obsolete and decrease airtightness, letting in more cold air.

Posted By: billyb_1234" The main issue relates to the roof coverings. They are old (some 90 years I would estimate) and at the end of their useful life expectancy. The photographs give some idea of condition. Patch repairs have been carried out externally in the past. Daylight can be seen in a few places from within the roof void. There is no underfelt. You will need to budget for new coverings, pre-treated battens and vapour-permeable felt".

If I was planning to stay, or do the roof conversion in a few years, then I'd fix any problems and hold tight for now - as others have said, from the photos the roof looks in pretty good order. The main obvious problem is the lack of underfelt; apart from being a secondary barrier against rain ingress, without it snow can blow in and melt. If you're not planning to stay then I'd re-roof now, using the same tiles, to make a future sale easier.

Posted By: borpinPut in cross joists so you can raise the decking and put thicker insulation down.

Take a look at https://www.loftzone.co.uk/storefloor/ as an alternative.

Posted By: billyb_1234I was considering the possibility of removing the stacks.

Worth doing, and if you take them down internally you can gain space too.