Architect’s build cost estimates - how accurate? 😬

[GingerAndTheBiscuits]

We’re in initial stages (concepts) of extension planning. We’re looking at a couple of different options - a ground floor extension (18sqm) with a modest extension over it on the first floor, or a ground floor extension with a loft conversion (medium sized bedroom and en suite). It’s a 1930s semi so a very normal sized house.

Alongside the initial concepts the architect has provided some estimates of each option. And they are eye-watering 🤣 even at the low end, ground floor plus loft option estimate is a quarter of a million.

Am I way out of touch? I’d thought somewhere closer to 150 and even that was pushing it. We are really looking for functional not fancy. We’re also in the midlands, not south east. Have other people found their architect to be accurate with this kind of estimate? Would there be any value in talking with a couple of builders at this stage to test the estimates? At this rate it’s looking like it could be cheaper to move but we were really quite keen to stay put if possible.

I have no experience of architect estimates however build prices are very high now compared to what they were and for most people most of the time moving is ‘cheaper’.

is this going to add any value of note to the property or just convenience for you?

It would add value in that it would enable us to put a modern kitchen in (vs the 40 year old shell of one we have now) and would either convert a box room to a more practical size or add a 4th bedroom and allow us to use the box as an office (both wfh). Realistically there is a ceiling price on the road we live on and spending 220k on the work would probably put us on the edge of that. However it is a great location that we could live in for the rest of our lives and would future proof the house for us. Would give both kids spaces that would accommodate them living here into early adulthood. We like our neighbours!

We bought cheap and our current mortgage is c80k - we’ve probably got about 100-120 of equity in the house but would need to spend a decent chunk getting it ready to sell. House prices have rocketed here so we’d be looking at at least 360k for the “next house up” which gives us the above, plus the costs of moving. Argh. It’s too hard to work out! I’ll keep doing the lottery and hoping for the best 😆

Following with interest!
Indicative pricing from our architect for a ground floor extension and loft conversion was 300K. South West.

Two architects in the family. Yep that's accurate. We looked at a kitchen extension pre COVID. All finished was £100k. Would be double that now.
The price of materials is out of control. A few months ago the price of internal plasterboard doubled in a month. Steel has more than doubled.

If you won't be in negative equity, are planning to stay, then it's worth doing. Just 🙈

Oh crikey, we’re not alone then! We chose our architects as they are local, know the local planning foibles and how to tackle them, and didn’t do any kind of hard sell. But they do seem to do more high end jobs so I was hoping their estimate was based on that and our more bog-standard approach would come in a bit cheaper. But perhaps not!

Ouch! If we did the work then I would plan to be carried out of this house in a box, so hopefully another 40-50 years to go!

Everything about construction is expensive just now - material prices have gone up massively post covid. What you could do is get the waterproof shell done and save money doing the interior yourself but that’s a lot of work and relies on you having decent DIY skills! And material costs will still be a bugger.

We’re a horrifying amount of time into our extension (two storey), but finally approaching the closing stages. We too thought our architect’s estimate was based on his normal high end clients, and that we might be able to save a bit. He was pretty accurate (around £350k, south east). We’ve only had one significant cost increase (reroofing existing house) over what was planned, but as others have said, building material costs have shot up. We have been lucky with our builder too.

We have put up with a lot, it’s not fun, but we’re so excited to have the extra space long term. I’m really pleased with how it’s shaping up.

Moving is obviously not cheap either! Good luck.

I think that’s part of it @StrongGirlsLift - part of me just wants to finally put into reality the ideas we’ve had for the house since we moved in 15 years or so ago. But that’s maybe a bit romantic and I need to be more practical.

Eye opening thread! I’m house hunting at the moment and everything seems to have a lot of work need doing. In my head I’m costing every scenario as ‘about £100k’. I’m clearly completely out of touch. My London loft extension 12 years ago was £25k.

Our experience with an architect was he way underestimated the costs so we had to make quite a few compromises on his ‘vision’. But I’d say £250k for extension and loft is not unreasonable. I live in a terraced road of three beds and lofts would be a minimum of £80k, and if you did anything like lowering the first floor ceilings(like me neighbours did) it could go way over £120k just for the loft.

Not lowering the ceilings @mondaytosunday though it was discussed - however to maximise space would need to go hip to gable end roof and a dormer so not cheap!

It's much cheaper to put a garden office in. And if your garden isn't big enough for a garden office your house is probably top heavy with the proposed extension
We are noticing as we get older how much we use the garden to sit in. Sheds are useful for storing stuff that would otherwise take up extension space.
Our neighbours have abandoned their big kitchen extension as they spend all their time on the decking outside the kitchen and suddenly realised they would lose that with an extension. Also it was going to be 300k minimum for that and the loft. They just did the loft and I think it broke them re building dust etc.
In our road no big extension would now recoup in resale. There is a 300k gap in what people are expecting to spend on upgrades and what price asked is...stalemate when it comes to resale.

I think the tired houses that already have extensions and lofts but need a bit of tlc are the best value in current market.

The strange thing is that round here everyone over fifty is living in houses that is too large and over extended; too expensive for people with young families to move into when it is priced to include all the renovation. Yet too large for people whose children have reached mid twenties and are relocating/pairing off. I wonder if the idea of a house that is the right size for every stage is a bit of a pipe dream. It's an awful lot of work extending only to find that ten years later the house is too big in wrong place not extended the way people want.

wow, that makes me feel very glad I'm not planning rennovations.

I though what I had in mind might cost £40k which would be a stretch but the prices here... neah. Completely impossible.

A garden office would be a reasonable compromise if loft is out of reach. I know what you mean about not over-extending the house to price out families - we are currently in easy reach of the town centre, supermarket, station and several schools so I think it would still have appeal. But lots to think about!