loft conversion & small side extension - need reassurance!

[dairymilkmonster]

We are in a 30s semi and my DH is very keen on doing a loft conversion (would be hip to gable apparently) and putting on a small single storey side extension (like a side return filling in) for a utility area and downstairs loo.
I am terrified at the prospect of a big project like this. Looking for reassurance that we can survive this !
We have had a measured survey and chosen an architect (I rejected the first two that came round as neither listened to us and what we actually wanted) who is drawing up plans of options. Side extension will need planning permission, loft is in permitted development.
My major concerns are:

1. Escalating costs - We are very early stages, so only vague costings have been mooted by teh architect but he thinks the extension (which is about 2.5m by 4m) and loft coversion (to make bedroom & shower en suite) will be £110-150,000 altogether, depending on our choices. We are in the south, in a very expensive area, so i'm expecting it to be costly. My worry is whether we could fix a budget and ever vaguely stick to it.
2. How on earth to cope during months of building work? Roof coming off, noise, dust, freezing cold, mess etc. Thought of coming home to a dirt ridden freezing cold building site for months on end is horrific. I am pretty rubbish at coping.

I think I have watched too many homes under the hammer/ grand designs type programmes where it takes years & costs triple to feel this is a viable project. If anyone has had anything vaguely similar done and has pointers, reassurance or anything else to add I would be very grateful.

No experience of ground floor extension but we have a loft conversion and I found that surprisingly easy. Most of the work is initially external so doesn’t disrupt you and even when they broke through it was just the upstairs landing mainly affected and not for long. Stairs arrive ready made and go in quickly. We found cost control ok but we had quite a basic spec - bedroom and bathroom, fitted wardrobes were the only extras. Just allow for things like bathroom fittings, flooring and furniture in your budget and get a clear breakdown from the loft companies of what they include.

Loft extensions are fine unless you have to lower ceilings.

We are just coming to the end of a project like this, in a 30's semi.

Our estimate was just over £100k for a loft conversion (including hip to gable), plus build over garage carried up into loft conversion and extended kitchen out the back to match existing utility room. We have gone over at moment but not by very much. So are going from a 3 bed to 6 bed house.

The loft conversion will come first before any work on a first floor extension due to the scaffolding required. All of this will be done from fhe outside, they will only break though into the landing when they are ready for fhe new staircase. So initially very little dust inside. We had it worst as we lost the whole of the rear kitchen wall due to a new rsj being installed to support the whole of the rest of the back corner of the house. We went from middle of August to January with a plywood and insulation board wall for the back of the house.

BUT have added extras onto costs due to unforseen work. Some suggested by builder and some had thought of myself but wasn't sure if a good idea, so ran by builder, who (unsurprisingly) said would be a good idea and then gave us reasonable quotes.
Extras so far, new larger combi boiler moved to new location, a lot of the pipework would have had to be re-done/routed if boiler stayed in old location anyway. Roof completely retiled, the builder was going to re-use the original tiles, but so many broke or cracked when removing it was just easier using new rather than 80 year old tiles (saved on scaffolding costs as it was already in place). Sofets and facias all replaced with plastic, this showed up some dry rot in the end of the rafters that wouldn't have been seen otherwise, so bad areas replaced as well. We're onto about £8k of extras so far. New internal doors will be about another £1k extra due to the cost of the ones we like over the buildrs estimated cost of doors.

One thing to think of is storage space, you will need to EMPTY your roof space. We ended up renting a 20ft container which we've filled with what was in the loft, garage and utility room.

Hope this helps, we've managed to get through it living in the house with 2 teenagers.

Thanks so much, really helpful. I hadn't thought of what to do with the loft contents, although DH says approx 50% of the volume up there are clothes, toys, baby related stuff we don't actually need anymore and could give away. So that will help a bit. My aunt has a large empty shed thing in her garden which she would probably let us put stuff in temporarily - I know a cousin has recently moved his stuff out!!

Boiler - we had a new one 2yrs ago and chose one with capacity to go upwards into the loft, so hopefully will be okay. I'm sure other things will crop up though!

It sounds like you have done really well at keeping pretty much to budget. I'm seriously impressed at going from 3-bed to 6-bed. This project will move us from 3 double beds + box room to 4 double beds, two of which are en-suite. (Latter due to my PIL refusing to stay unless they have an en suite !!). Both DC rooms, our room & spare room will all be really good size. We already have 3 receptions downstairs + large kitchen diner, but No utility space. So whilst the number of bedrooms & receps won't increase, we will improve the size of rooms. It would have been great to keep the box room, but apparently this isn't possible with the staircase. We will get storage space in the remainder of the boxroom though, which is great.

Our DC are 7 & 3 currently. I don't think they will be that bothered by the work, it is more me.

Thanks.

We got lucky with the stiarcase, our landing is wide large enough that we didn't loose any space in the box room for it, which is why we've gained another bedroom. 6th bedroom is also in the loft, but is down as a store room in the plans.

I should have said that our estimate was to plaster and 2nd fix only, no decorating, or kitchen fitted. I've just got a lot of decorating to do.

One thing that I'm getting done whilst the building work is going on, is to install network cable into every room, for a home network/internet connection for faster speeds as the house interferes with the wifi signal.

Which part of the south are you in? I'm about to have quite a lot of work done and it's way cheaper than that .. I had loads of quotes and the builder we chose wasn't the cheapest . Our next door neighbours had a loft conversion and it was no where near that cost .

Even in an expensive part of the south you should be able to do both for 90k, budget 35k for small ground floor extension and 55k for loft. This is far more than I would spend but you said expensive area. However people have done these for less in London but it's all down to what you buy and how much your labour costs.

Thanks for all the advice. The costs are just what our architect has roughly sketched out for us. He might have been giving the worst case scenario. We might be lucky and it work out less! WE won't be going for anything bespoke or indidivual - we are quite happy with basic stuff and fittings from ikea etc. We will need to have skylights in the roof of the side extension, because it otherwise will be very dark.
I will certainly get a variety of builders round when the time comes. We have had one previous very bad experience with a set of builders who were the cheapest and were a complete nightmare, and that was only a tiny job!

In my experience architects either aren't in touch with builders current prices or they over exaggerate . Get basic plans drawn then get loads and loads of quotes .

Would it increase the value of the house by the amount you are spending? I would be concerned at not gaining extra bedrooms.

You have a decent budget, I would expect the cost to be under 100k to be honest maybe even as low as 75k depending on finish

£110-£150,000 sounds very expensive for what you're having done. We have nearly completed our roof conversion (just the painting, carpeting and ensuite installation to go) and it's coming in at about £75,000. This is expensive for a roof conversion, but a) we're in the south east; and b) our house is detached and has a surprisingly large roof space with weird shaped roof, which pushed the costs up. The building work really hasn't been a hassle - there is thick, gritty dust in random places including nowhere near the roof, but other than that it's all been pretty easy.

Your plans sound great but I do agree with Elektra re being sure that you're increasing the value of the house by the amount you're spending.