Conservatory subsidence, repair or rebuild?

Homeimprover919

Hello MS Experts!

I am after some advice! Sorry its a bit long!

A few years ago, I noticed cracks both indoors and outdoors where my conservatory met the rear of my house.

Conservatory is solid brick walls at both ends, and dwarf wall to the rear, with a polycarbonate roof. Its quite large at 5m x 3m and is open plan with two openings into the house (which should have upvc doors but previous owners removed them)

I made an insurance claim which of course resulted in a survey etc and ultimately in the insurance company confirming subsidence but rejecting the claim on the basis that the conservatory was not built with sufficient footings.

Both the survey company and a structural engineer I later appointed myself said that the problem had been caused by 10 large leylandii trees forming a hedge between my neighbors property and mine and that if I removed them, it would solve the problem. I removed them all, the ground rehydrated and the conservatory moved back into position and has not been a problem for 5 years.

I have wanted for some time to convert the conservatory to an extension initially by replacing the roof with a solid one. My structural engineer advised that this will be acceptable to building control with the addition of steel 'goal posts' both around the opening from the house into the conservatory, and at the rear of the conservatory - even with the history of subsidence.

My question:

Would there be much difference in cost between installing a lot of steel and a flat roof, plus new windows throughout versus knocking it down and building an extension from scratch

Section62

Homeimprover919 said:

My question:

Would there be much difference in cost between installing a lot of steel and a flat roof, plus new windows throughout versus knocking it down and building an extension from scratch

If it were me I'd rather be able to answer the question about insurance claims and subsidence with the honest answer that an old and defective conservatory had been affected by trees, but that conservatory had been demolished and replaced by an extension which was fully compliant with building regs.  For me the ability to do that would be worth paying a premium, even if there weren't other issues.

Needing to do a fair bit of remedial work to end up with a conservatory extension with solid walls, probably a solid uninsulated floor, and with a past history of movement, doesn't sound like a very good idea.  But at the end of the day if you don't have the budget to start from hole(s) in the ground then making the best of what you've got is second best.

Homeimprover919

Section62 said:

Homeimprover919 said:

My question:

Would there be much difference in cost between installing a lot of steel and a flat roof, plus new windows throughout versus knocking it down and building an extension from scratch

If it were me I'd rather be able to answer the question about insurance claims and subsidence with the honest answer that an old and defective conservatory had been affected by trees, but that conservatory had been demolished and replaced by an extension which was fully compliant with building regs.  For me the ability to do that would be worth paying a premium, even if there weren't other issues.

Needing to do a fair bit of remedial work to end up with a conservatory extension with solid walls, probably a solid uninsulated floor, and with a past history of movement, doesn't sound like a very good idea.  But at the end of the day if you don't have the budget to start from hole(s) in the ground then making the best of what you've got is second best.

Thanks for the detailed reply!


I agree entirely, in fact it’s the exact reason that I asked. Hopefully someone will have an idea so we can start to get some quotes !

Albermarle

When the cost of building a single storey extension is mentioned on the forum, you usually see figures from £2000 per sq metre to £4000.
Location makes a difference, as does the level of finish. The lower prices might just give you a watertight box, with no electrics for example.
Also can be plus VAT