How's this for an approach

Quiet Achiever

Doing everything except the walls... Why?

Sale agreed on a 70s cavity block house. V poor BER rating. Otherwise turnkey condition.

Currently live in an a2 house where everyone in the estate finds large parts of the house cold, likely due to air tightness.

So, for new house i want to insulate under raised floor, new windows and doors, new gas boiler, and as much as i can on the attic. Then, importantly, do a very thorough job on ensuring it is airtight.

Then just live in it for a year and see if it "feels" good enough. As feeling warm and a good BER i read and have experienced are not always the same.

Logic is that the internal insulation is disruptive, the house has a lovely finish already, and i cannot do external. I don't care too much about BER or one stop shoo, i can go to different vendors and claim back myself. And if after the year it feels too cold then, do internal insulation for all or just some cold rooms.

whizbang

Here's some insight into 70's cavity block construction…I will let you decide on the Cost Vs Benefit.

1 1st floor Joists. All gaps open to cavity

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2. 1/4" Dot Dab plasterboard removed

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3. Wallplate. Can almost see daylight thro the crumbling cement.

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4. Finishing Internal insulation

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Quiet Achiever

Wow, i really appreciate you putting all of that together. I suppose the fact is we don't know what is there until we pull the plaster off, so any talk of air tightness is moot...

monseiur

With respect there's no logic to what you're planning. If your were feeling cold would you put on a pair of warm socks & boots and a Ushanka and nothing else….well perhaps a fig leaf ! Do it once and do it right. So include dry lining of all ''external'' walls in your project. It's pointless having an airtight building if heat is seeping thru the walls! Once your house is warm & cosy it won't cost a fortune to re create the present lovely finish. If possible consider replacing the raised floor with concrete. Upgrade your attic insulation to at least 300mm

As for BER ………well let's just say that some assessors's mode of transport is a horse, wear a stetson with a six shooter on the hip.😢

Quiet Achiever

Again, appreciate the feedback.

I'll do it all, and am going to avoid the one stop shops. First thing is to get rid of the oil burning range and put a new gas boiler in the boiler house outside. Then get the walls, attic, and floor done (not concrete at this point).

If anyone can recommend a really reputable insulation company by pm then i would appreciate it and it would be your good deed for the day :)

ted1

Do nothing. Move in and see how it feels.

We are in an 80s semi. ( Al though moving shortly)

the houses are actually fairly good. Some people who move into the estate do a massive job on insulation. Etc before they move in and are then shocked when they visit a neighbours house who has done nothing.