48sqm kitchen extension. £30k all in

21 Oct 2014
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West Midlands
United Kingdom
So here it is; my side kitchen extension project from start to finish (almost). I had considered posting incremental bits and bobs but felt it more worthwhile just to get it done and post in its entirety. Hopefully some other budding DIYers will find it of use and hopefully those who have taken the time to offer me advice on this forum will enjoy seeing the fruits of their labour or have a bloody good laugh!

Firstly a bit about me and my ethos on this project. Having recently moved to a new house we had a bit of money left over. Not much, but probably enough to bring a 1925 property that was untouched for about half a century into the modern age. The layout is great, all the rooms are big with high ceilings and great features. But, the kitchen was small and in a mess. We very much like the idea of a big kitchen/diner which was certainly not in the mindset of those who built it nearly 100 years ago. So it was decided to use that pot of cash to extend the kitchen, create a utility room and a much needed replacement to the outside toilet as we will unlikely see a pot of cash like that again. Decorating individual rooms is doable on monthly savings where as saving for an extension would likely not happen.

Requirements: large kitchen/diner (40sqm), utility room, downstairs toilet. (Total 48sqm)

Budget: £30k all in including kitchen and appliances.

Now as you can probably tell, budget is tight. But luckily not as tight as me. It was immediately obvious that a large proportion of a build is labour. All the skilled trades need to make a living. So first off, rule out any labour. My time is free. Second biggest cost is materials. With my slow progress I can spend time looking for best prices. eBay, seconds, discounts etc etc. I don't need everything all at once from Jewsons. In fact I bought nothing from these places.

Reuse, beg, borrow, buy is my heirachy along with a no skip policy. £200 a pop mounts up when you could fill 10 of them. I've got a 6x4 trailer and a local tip 5 minutes away. They know me very well! Looking back I'd be hard pushed to save much more.

The one small issue that stood in my way is that I have no design or building skills or experience. In fact anything that is required in a build I have not done before. How hard can it be? I have youtube, Google and this forum. I'm sure every tradesman didn't bother wasting time on college, exams, apprenticeships and the likes and just watched a couple of how to videos.
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Here is the front and back of the house. Down the side of the house was a brick outhouse containing an outside loo, coal shed and workshop. This was linked to the single storey kitchen by a rotten lean to. The idea was to knock this lot down, bash out the kitchen wall to create a much larger kitchen diner, take up part of the garage as a utility room and downstairs toilet.
Architects and designers are expensive. So get a free copy of SketchUp and do it yourself! I had several issues constraining me apart from my lack of ability. A large landing window I did not want to loose, a dislike of flat roofs and getting light into a large deep room. After much deliberation I came up with this design much to the amusement of many seasoned pros on the forum, especially my over complicated hidden flat roof design.

Drawing pretty pictures isn't going to get this past building regs. I had decided I could do this under permitted development but building regs still apply. Lots of looking at proper drawings, lots of questions on the forum got me to this effort. My nice colours and textures provided great amusement so they were removed for the submitted plans. But I put them back on for here because like them. One day everyone else will catch up. To my great surprise I got approval

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Now for the bit I'd been looking forward to. Demolition. A bit of graft but little skill required. Right up my street. I saved the tiles as they match the roof and most of the bricks for future projects along with the engineering blue paviers.
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Digging. Lots of digging. This was hard. Long slogging days that felt like they weren't going to end. The topsoil was really crumbly and always wanted to collapse in on itself. In a 600mm trench you can stand and dig but in a narrow drainage trench you are there with both feet in front of eachother with your shovel reaching out in front. Soul destroying. Felt like I was in world war one trenches.
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Drains. Getting the right fall wasn't too bad. I'd ripped out an 8m mid section of clay pipe which had the correct fall. I just had to follow this with my new plastic along with my new branch lines for kitchen island, utility and toilet waste
First building inspector visit was nerve racking. I knew he was going to clock me for the clueless amateur I am so I just swatted up on loads of facts and figures and gave him a running commentary as he went around with his clip board. Whether he was impressed or annoyed it seemed to work. He just complained about the base of the trench having topsoil in (due to my friable soil issue) and said I needed to go deeper. I basically scraped less than an inch out and the next day he revisited and gave the all clear.
Foundations. I had to shutter off the drains. Being a skinflint I saw 11mm OSB was much cheaper than ply or 15mm OSB. I was soon to regret this. Got a cracking price on concrete and had 3 Weetabix on the morning of the pour as the back trench had to be barrowed. Half way through the shuttering was bulging. Then it gave up the ghost. Luckily I had a load of timber I managed to wedge in and stop the concrete avalanche causing me a world of pain. The front went much smoother. I swiftly levelled off and felt a sense of achievement I was now out of the ground. Pea gravel all around the drainage then backfilled
Kitchen wall removal and steel beam. I now had a dilemma. I had already decided the extension would be rendered. My reasoning was that as I could not find a brick match or anything close I would rather go totally different rather than a poor match. However render doesn't go below DPC so I needed the right bricks for this. So the idea to remove the kitchen wall at this early stage and use these bricks below DPC came about. I needed steel beams to support the rest of the gable end and found out that below a certain length building control did not require structural engineering calcs. Suited me as that ain't cheap. Asked questions, googled the hell out of it and settled on a pair of beams that I'm sure are well above what I needed. Cheap too! Getting them in was a giggle - had to enlist an equally well qualified mate and explain the site health and safety procedures..... We are going to use flimsy ladders and lift those big steels on our shoulders into that almost exact gap whist wearing flip flops. Job done. I could now remove the wall to reclaim my bricks
Bricklaying. Luckily for me I am equally experienced in bricklaying as I am in other building skills. A godsend is the plastic bricky tool. Not sure what builders on site would make of a new brickie turning up with one but no one was watching me. Took an age but came out alright. I thank the baby Jesus I had decided to do the rest of the build in blocks. I'd still be doing it now otherwise. Building inspector visit number 2 followed without a hitch. I got the feeling he now had a little more confidence in me and thought me less of a chancer
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Floor slab. Insulation is expensive. Especially PIR celotex type. Googled the hell out of U values even though I'm still not sure what they mean. But I realised I could get away with expanded polystyrene as depth of the floor wasn't an issue. In fact I had a good bit of height to make up. Fitting a massive DPM on a windy day on your own is no fun. I'd have made a sailor blush. All down and ready for concrete pour number 2. I was fully aware this was make or break. 7 cubic meters of concrete being poured with just me to make sure it was flat is a big ask. I was fully aware how wrong it could go very quickly. Hired a bull float with enough poles to reach down the end of the road and just went for it. No point in dwelling on the pitfalls. Lady luck was on my side and managed a fair effort. Reasonably flat and level. Walking over it once it had gone off made me realise I was on the up. No more mud, just a solid base to start the real build.
Block work. Back on the trowel. Although faster than bricks I was still slow. Not sure if 25 blocks a day would land me a job on site. To add insult to injury I had to build 2 walls to make a cavity. Twice the work for the same increase in height. This dragged on. Started to loose the will even though I had convinced myself this was a new era of the build. Summer was drawing to a close and I wanted to be water tight for winter.
Roof. I was elated my blocking days were done, but nervous of the task ahead. I'd been mocked about my roof design, it was overly complicated and intricate and I have no roofing experience. As mentioned I have no experience in any area, but the roof was daunting. An easy break in was the flat roof joists but they needed to be hidden with the mono pitch going all around. Angles, compound cuts blew my mind. God knows how I managed it but it seemed to go ok. All in line and seemed sturdy. I had a 3 day good weather window to get the warm flat roof on and fibre glassed. Cheap seconds insulation off eBay along with a GRP kit would get that sorted. To be honest, apart from my limited timeframe, it all went surprisingly well. Panoroof rooflights collected dropped in a treat. 80kg up a ladder with several hundred quids worth of glass on your shoulder is quite invigorating. 4 in total, 2 in the kitchen, 1 in the utility and loo. Safety flip flops a must. Flat roof done I moved on to the pitched roof membrane and battens. This was more of an issue as I'd procured Arris hips and valley tiles to match the house so the battens had to be continuous around 4 sides. I'd spent time making sure my rafters were bang on but I still had to loose a few mm here and there. Winter was in full swing, it was snowing and I was tiling. Passers by must have though me nuts. In fact I thought it. Sweeping snow off the last days work to progress with numb fingers was no fun. Eventually water tight. Another milestone.

Windows and doors. Got a cracking deal on these as a friend knew a bloke in a window factory. The composite door was an ex display model. All a bit bitter sweet as days before they went in some of my tools got nicked. I was clearly becoming complacent and hadn't locked them in the garage but just had them inside the build which had a sheet of OSB leaning against the door. My 18v drill, impact driver and 36v sds went. Bloody livid at my stupidity and the nerve of someone robbing me. A couple of weeks scouring fleabay and gumtree looking for the crook to no avail. Probably just as well as I'd probably be inside now! Fortunately the rest of my tools were left as the smack head could only carry the better items. Anyway, doors and windows went in a treat. Pleased with the 2 sets of French doors, both 6' although a slight compromise as ideally would have gone for bi-folds spanning the whole back. But under a grand for both sets was a quarter of the price of the bi-folds. This enables me to do the rooflights and still have plenty left. A wise choice seeing as there are no windows in the utility and loo. Now I was fully enclosed.

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