Ballpark cost side return and loft extension London

[Saschka]

We’re looking at moving from a flat into a house, and all the “done” houses in our area are at the top of our price range and going to sealed bids. And also some questionable design decisions, like the fridge and washing machine in a shed in the garden. But there are loads which haven’t been renovated which are 30% cheaper, and seem to be sitting on the market (£800k Vs £1.2m).

Just trying to work out whether it is worth buying one of those and doing the side return/extension down the line. If the price is likely to be <£350k it’s probably worth it, if not then it isn’t.

So, is anyone doing theirs at the moment, and if so what have you been quoted?

Depends where in London. We’re just finishing our loft (SE London) and incl bathroom it’s cost 75k.

Thanks! We’re in south London too, Herne Hill at the minute, looking around east/north Dulwich.

Does the rest of the house need doing up? SE london spent probably 140k on general renovations including side return & new kitchen / bathroom but no loft

I know the area. I'd say £150,000 plus for the side return and £75,000 plus for the loft.

We paid 90k for a side return in a similar area of London last year and were quoted 70ish depending on options for loft conversion

Nothing structural - just painting, floors etc. Back extension would be knocking through kitchen/living room, putting in a downstairs toilet/shower room and extending by a metre or two out back, loft would be bedroom only, but we’d re-do the family bathroom.

These prices are sounding much more achievable. Any company/architect recommendations? (Or people to avoid)

OP the problem is, it’s not going to be just a side return and the loft… we’re halfway through similar works and to do the loft, we had to completely replaster a bedroom (to reinforce walls), change the roof, rewire the whole house, get a new hot water cylinder (because the old one was in loft), then move it to where the downstairs loo was, so we might as well move the boiler, since we’re changing that then we changed the central heating system, all new radiators etc!

you can’t underestimate the cost for the “associated” works 😫. Our loft itself was expected to cost £85k tops, but I suspect we’ll end up closer to £150k.

Ok, bear in mind ours was just side return, no wrap around and no downstairs toilet. Id recommend our builder, if you dm me i can share details

Hi OP,

I live in that area. We have recently been through a loft extension and have had many other friends in the area do the same and side returns. We have permission, drawings and calculations for a side return but chose not to do it (reasons on that below).

The final figure is going to really depend on your fixtures and fittings. Based on our own works I’d say:
Ground Floor Extension: £90-100k including putting in the downstairs toilet
Ground Floor Extras: £50k for kitchen (skys the limit though) and toilet
Loft: £60-£75k inc. decorations if only a bedroom.
Family Bathroom: £15k (assuming good quality but not complete luxury fixtures and fittings)
Decoration: £10-15k. After these works you are likely going to need your entire house repainted due to dust and knocks / damage from the works.

Some thoughts / final points:

• with current prices, do not expect change from £250k to do a loft and side return extension in SE London (factoring in contingency, unexpected costs, cost of plans and architect)
• why only the bedroom for the loft ? Assuming you but a standard Victorian house which is typical for the area (like ours), you could probably fit one large bedroom, a bathroom and a smaller bedroom up there. Once they are up there, the cost of doing just the bedroom vs extending the whole way for extra space is minimal.
• you will make your money back on the loft, very unlikely on the side return. We bought in 2021 for £750k. Did a high spec loft extension for about £100k. House now work £1m. Side return could take us to £1.1-1.2m depending on market, it just wasn’t really worth it.

Do the loft. Only do the side return if you plan on making this your family home and will live there for years to come.

How much space in sq.ft are you wanting to add, OP. Not sure why this question is always asked without this crucial details only to invite random answers like, ‘not sure where in London you live or how big the house is, but we paid £4.98 for our extension in 1972’.

@AmIOverthinkingItOrNot I agree on the different value add of the side return Vs loft - we love our side return extension and it's transformed the house but I don't think it's added as much to the value as it's cost us. We plan to live here for 20+ years so worth it to us but we wouldn't have done it if we planned only to live here for a few years

We did exactly that last year in SW London and it was 250k. We don’t plan on moving so not concerned about making a profit but I’m confident we broke even, but that’s really because of the loft not the side return.