Tell me about your two storey rear extension - what do I need to know?

[SheWouldNever]

Starting to plan our two storey rear extension. Going out 6m on ground floor for new open plan kitchen / dining room, and 4m on first floor. Existing bathroom will be turned into hallway leading to new master bedroom, and the smallest existing bedroom will become the new bathroom.

Those of you who’ve done two storey extensions - what do I need to know? Do you have any tips / advice that you’ve learnt from the experience? How long did the build take?

The rest of the house also needs a full refurb, rewire and replumb, so we’ll have to move out for a good portion of the work. Am I being naive to think that we could live in the house whilst the extension is going up, then vacate at the point it’s knocked through, at which point the rest of the house refurb can also be done? In my head, that would minimise the time we’d have to spend living elsewhere with our stuff in storage, but I know builds often don’t work out the way you think they will in the beginning.

We are in the middle of a double story side extension. It was meant to be a 12 week build but will be at least double that.
We have done similar to what you are proposing in terms of living there and then moving out for the knock throughs. It might depend on whats happening with the gas and electric as to whether it's possible. We had the boiler moved temporarily and the same with the electrics. We moved out for 5 weeks but really would have been better to stay away for at least another month. In hindsight I wish we had budgeted to move out for the whole build.Its dusty, messy and noisy.... And we have builders that like to be tidy.
Good luck.

Also make sure you get a fixed price as if it does run over in terms of time you don't want to be the one paying for it.

Do you have your builder signed up? We recently did a two storey extension, although it was mostly a separate box on the side so less mess in our existing house. We sat with the builder before and talked through the order of the build, exactly when would things happen or be needed and at which points we would have our existing space or services disrupted.

Plumbing was a big thing to plan, we turned a box room into a bathroom and so all new drains had to be laid underneath the new extension area.

Wiring the new parts meant we had to have exact plans drawn up of circuits, switch locations, light positions etc before the electricians arrived. Thinking about dimmers, which lights you want to turn on from where and circuits was definitely worth doing in advance! I drew colour coded plans for these and now have lights and lamps working in a useful way in each room.

@PragmaticWench no builders yet. We’re v early stages so looking at architects and need to apply for planning. New bathroom will be right next door to the old bathroom, and directly above downstairs shower room and toilet, so I’m hoping the plumbing won’t be too tricky but I have no idea.

We did a rewire in our previous house and wished I’d planned it better / had more time to think about it.

@Username54789129671 the electrics and plumbing in the existing house is utterly ancient so I’m fully preparing for builders to tell me they’ll need to tackle that first, which would mean us being out for the whole build and refurb. I’m thinking 6 - 9 months, but was hoping we could maybe shave that down to 3 - 6 months living elsewhere if they can start with some of the external work.

Were your building delays due to covid, or unforeseen factors in the build?

We did 2 storey to the side and rear, with a full refurb it would have been impossible to stay at home. They gutted the whole place!

My advice would be to move out whilst the work is taking place. Also it will take longer and cost more than you think.

Are you detached? Even at this stage, chat to your neighbours about what you're planning and listen to any concerns they have, they're going to be inconvenienced by the work and it's better to have a good relationship with them.

We lived in our house throughout (other than a summer holiday). We lived in 1 room at the front of the house with a temporary kitchen (well, a kettle, slow cooker, microwave, George Foreman & a bucket!) and 1 bedroom + box room upstairs. Wasn't easy with 3 primary aged children but do-able. Builders were great.

Tips - plan for it to take longer and cost more. There was little of the house that wasn't affected in some way. Budget for your back garden and probably your drive to be trashed and to be landscaped / block paved afterwards. We waited almost a year for the builders as they were highly recommended - definitely the right decision.

@Africa2go semi detached. Adjoined neighbours are just coming to the end of their own 2 storey extension, we’d be mirroring what they’ve done.

We did a double storey extension about 12 years ago with a new baby and toddler, we managed not to need to move out but it was dusty. The builders were fab and did as much as they could before knocking through.

We had a temporary kitchen split between a downstairs study and utility room. Moved out to my mums for 2 nights but only because there was a problem with the gas supply and it was middle of winter.

Building work went more or less to plan with maybe a 2-3week over run over 3 months of building work but it was a little longer before we had a full working kitchen.

We did a full renovation (but not extension) on this house whilst we were living here (and we extended our last house whilst living there and when I was on maternity leave). Living here was messy but doable. We had the house rewired in stages, and then finished the lounge off and two bedrooms upstairs. We used those as our living space /sanctuary for the rest of the work. But the house was fully replumbed, rewired, and had a new heating system put in. We were able to vacate parts of the house that were being refurbished, and got on ok, but it’s quite a large house. We did have quite significant structural work done in the kitchen and were without kitchen for 14 weeks. It was actually ok.

Sorry, should have said significant structural work on one end of the house, from ground to roof level, so the dust was comparable to extension knock through I think (chimney stack removed, so very very messy)

@Flamingolingo were you able to do the plumbing in stages, too?

I’ve been wondering about the possibility of doing the refurb in stages so we can keep the front bedrooms and living room intact throughout the rest of the work, but I’m not sure how urgently the plumbing needs replacing (we’re not yet completed on the house yet so I’ll be able to investigate more once we are in).

@SheWouldNever the delays with our build have been partly due to lockdowns and people having to isolate etc, but also I think because the builders are so busy and juggle a few jobs at once and I think they have taken on too much, although they would never admit it I'm sure.

We did a substantial single story but times wise took 18 months from start to finish with planning. 4 months of that was waiting for the builder to be available but that isn't unusual.

However, I would suggest you discuss with the builder appointed assuming they are project managing the whole thing and you are not just bringing in trades? It is possible to just wire up the extension as separate circuits and then do the main house. Frankly more circuits is better especially with kitchens due to the landings with ovens and induction hubs which often need a dedicated supply to each of them otherwise you will suffer repeated RCD trips.

Don't underestimate how long this will all take but it is possible to live in the main house while the extension build is being done but then get out once the main renovation starts

The heating system was done over the space of a week, a couple of weeks after moving in. That was fine to live through, it takes over the whole house but is not that messy. The boards have to come up but they go back again the same day.

The rest of the plumbing was done in stages, including a new mains water supply, two bathroom refurbs, a new hot water tank, new plumbing to the kitchen, a water softener. That was all fine.

The electrics made a big mess, but we did that sort of in stages too. Then once we had made most of the mess we started on decoration and made some of the house nice to be in. Then got going with the big structural work. The whole project took about 8 months start to finish.

It will be more efficient for your builder if it is unoccupied
This will be a balance of what that increase in cost and value is in finding somewhere else to live , time saved on builder not having to clear up and work around you
Get a quote from 3 different recommended builders
Costs can increase because of unforeseen problems but also higher expectations as you go through the build ie if one room is completely new the existing one may look tired next to it

I wish we’d have moved out, I definitely would budget to do this if we ever moved and refurbed again.

Check on what’s being done regularly, there were a few things the builders either got wrong or perhaps chose to take the easy way out of!

Gardens front and back will be trashed - budget to restore.

The rest of the untouched parts of the house will need decorating again once the build is complete.

Have more plug sockets than you think you need. Create a tucked away charging area in the kitchen.

When you think it’s not moving very quickly and not much is happening, suddenly you reach a point where it all starts to come together and the end is in sight!

Finally, notwithstanding any of the above, it’s so worth doing.

The other option is to do the extension first then go and live at that end a d refurb the rest of the house.

We did a two story side and rear extension last year. 3m out back and 1m outside to create open plan kitchen diner downstairs, new bedroom upstairs and move the bathroom to create corridor to new bedroom. We also re-floored and re-decorated rest of house and did the driveway.

We moved out about 4 weeks into the build. The dust, the dust, the dust! The noise...but mainly because new steels were needed which meant walls had to come down sooner so we couldn't stay. Kitchen and bathroom ripped out 6 weeks in so the house would have been very difficult to live in. We put everything in storage to save it from dust and allow space for re-decoration.

The builders say they could have worked round us but it would have been more expensive, taken longer and our lives would not have been fun

I would 100 percent Chuck your stuff in storage and just move out.

Currently in temp accommodation whilst we go through this. Build started nov 2, due to finish in April. We move back in 4 weeks. Whole house is being rewired and replumbed, loft conversion and two storey side extension and rear ground floor extension. We stayed whilst the external brick work was completed, they started knocking through on our last week. The whole house is a bomb site, we couldn't have stayed. Currently no water, electric or gas! Even if we hadn't have been planning to redecorate throughout, there isn't a room that hasn't been touched.

Watching with interest as I could have written this myself!

We bought a derelict house last year which needs full rewire, new plumbing (currently lead!), new roof plus, full refurb have a small 2 storey extension planned. We've put in planning, but still working out which builder to use.

We are living in a small static caravan in the garden. We have heating, plumbing, kitchen etc and can get away from the dust and noise of the extension and building works. Would this be an option? Being onsite now has been much easier in terms of meeting contractors and to see what is going on.

Dont forget about the roofline of the extension and how it will fit with what you currently have? Will you have underfloor heating? Will your current boiler cope with the additional rooms? Are you adding in extra insulation? We are just starting, but very glad to have a sanctuary to get away from it.

Have you spoken with the neighbours about their builders? It may be that they'd let you see the work and layout, and you can ask if they're happy with their builders.

@WaterBottle123 that sounds really similar to what we plan to do, with the exception of the loft which we wouldn’t yet have the budget for. How long did your build take all in all?

@Catnuzzle So you were living there for 2 or so months whilst brickwork was going up, then out for how long before you think you will be back in? A few months living elsewhere?

@Eleoura

not much chance of a static caravan I don’t think. We’re a family of 6 plus dog and cat so would be a squeeze! We do have family close by, and we imposed on them during our last whole house renovation, but that was more like 2 months and I’m worried this could well be 6 months+ so hoping to reduce the amount of time we have to impose on family if we can! Current boiler is ancient so we’ll be getting a whole new heating system, and I think upgrading the insulation too. Probably won’t opt for underfloor heating.

@PragmaticWench we plan to speak with the neighbours and get a quote from their builders if they were satisfied with them and the build.

@Flamingolingo yes definitely an option for us to all live and sleep in the extension / ground floor, whilst builders are working on the first floor rewire / replumb / plastering etc. But I imagine they’d prefer we were out of the house for that bit and would probably be faster if we were!