How to set out FOUNDATIONS FOR HOUSE EXTENSION to save THOUSANDS..architect shows you how 

Thanks a lot for your kind words, it really motivates me when I get comments like this.

This is exactly why I subscribed also. Thank you for your videos 👍

Thanks a lot. Really appreciate your comment

Thanks a lot for taking the time to comment and best of luck with your project. I hope it’s rewarding. They usually are

Thanks a lot for the encouragement. Even in euros, that’s a hefty price tag and you’ll find once you have your foundations and sub structure in, prices will be easier to negotiate if you go the separate trades route as it’s then easier to price. You’ll enjoy it and be surprised at how straightforward (I don’t mean easy 😉) it is if you prepare. Just watch doing concrete in January February time when for curing temperatures. Thanks again.

Thanks a lot for the comment.

Thank you for that, I really appreciate it. It’s great to get comments and to answer any questions. Yes…. There’s plenty more on the way.

Thanks a lot for saying so. Let me know if you have any questions

Thanks a lot for your comment.

Thanks. Appreciate the comment.

Thank you and best of luck with your new property and the extension.

Thank you.

Best of luck with it. It’s the most rewarding way in my opinion

Exactly that. Get the datum clearly established, then all you focus on is keeping it plumb and level, and the 3-4-5 triangle. Thanks for your comment.

Hey thanks for the comment. Provided you don’t live in a terraced house, you can project 4 metres from your rear wall. The height of the eaves should be no more than 3 metres and the maximum height of the extension should be no more than 4 metres. If you’re in a terrace or semi detached I think it’s 3 metres max projection. The maximum length of your extension should be no more than the length of your house. Hope that helps and best of luck with it.

If it was block and brick, I might use shallower trenches for a strip foundation like here, build up to ground level and a bit above to form the shuttering for a concrete floor slab, or I might just pour the slab making sure to thicken up the edges where the walls are, and add some rebar. I doubt I would ever do a shed in anything other than timber frame, and for that I’d just mini pile it. But nothing wrong with doing it your way, I just think it’s more work.

You shouldn’t need to be compacting. I think you need to dig deeper, however, I can’t give you advice without seeing it and you need to contact a structural engineer for guidance. The soil needs to be naturally compacted if it’s a strip or a pad foundation, no amount of manually compacting will achieve what boulder clay achieves. The only exception would be it’s a raft foundation that you’re considering. I’ve made videos about how to know what you’re looking for regarding load bearing soil, but again, always talk to an engineer.

Hi. Are you in a conservation area, is your garden still twice the size after the new extension, with your warm roof, is the height below the permitted development requirement. Area wise it’s ok but there’s too many variables to tell you definitively , and you’re best to look at the government’s permitted development guidelines which is all explained using graphics so easy to understand. Best of luck.

Yes, that’s best. Just couldn’t get anything in time for this particular project.

You need to make an application for building regulations approval to your local authority using their building warrant portal. And then you can go the full plans route, or the inspect as you go route. For a self builder,,, full plans route is always next. For your foundations, you will need a structural engineer. I made a video about the process here How I designed this House Extension - start to finish, all the stages ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-DM5IZMAEQ4o.html Best of luck.

Thanks, I will check it out.@@build-better-things

Provided it’s conventional strip or pad foundations for a simple shape such as a rectangle, I’ll aim to always do it myself and keep control. The cost of delays due to people not turning up when they say they will at this stage are always substantial. I’d also rather do all the below ground drainage myself and know it’s in the way I want it. The skill in this phase is in preparation and logistics , which anyone can do if they take their time. I’d use groundworkers if pile foundations were required, or perhaps complex steel reinforcement that requires experience and skill, or for concrete retaining walls. I’d also use them for basements where a guarantee might be required, for example. Thanks for the comment.

Thanks a lot for your comment. They needed to be deeper for two reasons. First was that the first 400mm was basically just loose backfill, so pouring to the engineer’s spec would have been a disaster. The second is that I’ll always try to use the existing foundations as a guide to depth assuming there’s no movement in the superstructure.

@@build-better-thingsusing the existing foundation level is best way as u know many times they throw backfill onto back gardens etc therefor that can’t be counted in depth of found dig 👍👍

​@@makg4655 ain't that the truth

You dig down, expose them, depends on where you are in the country, but likely, they built the walls off the bedrock or went down to super solid boulder clay, and as you say, they would not have used concrete. When I’ve done it in the past, I’ve underpinned with the new concrete found, tied into the old walls with steel rods or mesh, and the new found sets over those ties making the whole thing act as one. Every situation is different however, and you need to dig your trial pit in conjunction with your structural engineer. Thanks for the subscribe.

@build-better-things Thank you very much for your reply. We gappen to be in Essex, so on clay. Thank you for the great content, it's very helpf.

I mention the need for trial pits before starting anything else. This is about strip foundations, assuming, after your trial pit, that the soil supports it. This is made clear in the video. For strip foundations you absolutely don’t need “fancy tools”. If after your trial pits, it’s clear that the soil won’t support strip foundations, then you have the choice between a raft foundation, or a pile system. For piles, yes you might need an auger. For a raft, yes, you might need a pump and form work. Passing building control is not really to do with what tools you’re using, and everything to do with the engineering, the design, and whether the foundation built on site is installed per the design.

I’m sure there’s a load of metal detectors and things you can get, I just go around and look at the properties to figure out the drains and the water and power, then if I’m in doubt, hand dig some investigations holes. You need to demonstrate you’ve got all the records and contacted the utility infrastructure companies, BT, gas, etc. they keep records that they will send you. Then if you need to call on your insurance, you can demonstrate you’ve carried out due diligence.

@@build-better-things thank you so much!

Hi. I’m not sure what you’re asking? What do you do if….?

@@build-better-things Hi. You said that you pin your extension base to the foundation block of your house. I cannot do that because my foundation is just bricks. I cannot send you a picture here obviously so I'll describe the best I can. Looking at the outer wall the foundation is made of bricks arranged length ways. The ends of bricks facing me going underneath the outer wall. Like the old fashioned boundary wall construction. I'm guessing I'll have to ignore the pinning of the base to the foundation of my house then. Maybe build upon deep piers to stop movement away from my house? Thanks

First I had set up some form work, then ready mix concrete wheelbarrowed from the lorry, and then placed with a shovel bit by bit. Tied into the strip foundations with rebar and the columns were fixed within resin anchored bolts. Hope that makes sense.

@@build-better-things it makes sense. How did you access that bit. Did you dig under the existing foundation or break through it?

Dig around and over if I remember correctly. Then resin mesh and rebar to tie in before form work and pour. The base of the existing foundations were the datum level so no need to go under, from memory

@@build-better-things interesting to know. Thanks

If you look at my videos on steel work, I think there’s one that shows it a bit clearly there. Thanks for your comments.

I use boards where there’s a need for shoring but I’ll usually aim to remove them as I pour the concrete. On your question about whether it’s necessary or not… not really uk specific thing, you either need to shore or you don’t. It’s not the regulations that dictate it…is the ground conditions specific to the site and soil you’re working with.

Foundations built at different depths and not tied to each other with reinforcement can result in differential settlement.

Hi and I hope you’re enjoying the uk. That is a 250mm thick strip around 600 wide, at a depth of about 1200 mm below ground. It has A35 mesh reinforcement with 35mm cover to the bottom. The steel column pad foundations are 500mm deep. All from memory but hopefully not too far off.

If you’re already a builder, do you want to run all trades jobs where you price and then build a job? For customers or for yourself by buying old properties and improving them ? For both, you need a working knowledge of all the trades, and can use tools for all trades when required, and be prepared to also have time for all the admin that goes with it. I learnt by mainly watching and then doing, although I did a few short courses as well. Yes I qualified as an architect which helped, but I don’t think it’s as important as understanding the whole building process, many architects don’t have much of a clue about that. Good luck and ask me anything else if you want since it’s a broad question you put.

@@build-better-things I agree with what you are saying iv learned alot of different trades. I guess I'm wondering what course would help me understand the whole process more. I wouldn't want to do a course in architecture to realize I should have spent the time learning something else.

Really I don’t think such a course exists. Sometimes we just need to dive in. The fact that you are asking these questions and thinking about the right things means I think you are in the right mindset to succeed. You can ask me questions anytime and if I can help, I will.

@@build-better-thingsI have done the perimeter up to dmc. I was going to add a cavity separating wall. I'm not sure how the procedure is to join the separating wall

To the perimeter wall and existing structure. Do I need wall ties on the dpc

One a flat and ones an apartment

Hi. This one took about a morning to set out and get all the tools, materials and plant on site for the dig. Then, due to the depth and the rubbish soil, it took about 2.5 days to dig, including shoring a few bits. So 3 to 4 days max if I remember right . Would probably have been quicker except we had to barrow all the soil to the front, we couldn’t get a mini dumper.

@@build-better-things thanks for your reply as it good to get an idea how long these things take. 4 days seems very quick and gives me when I start my extension I’ve got a ballpark figure how long it will take. I’m quite anxious even though I have experience with DIY but after watching your videos it’s really open my eyes to what is possible.

Allow a week. Make sure you dig the trial pits first.

@@build-better-things thanks for the tip

I don’t know what you mean. Guttering Would be part of the roof work, not the foundations.

Didn’t I explain in the vid? I thought I did but I’ll try to find the timestamp.

I used to dig that out in 2 days on me own 🙈

It’s not about whether it is wrong I guess, it’s about the damage that’s caused by incorrect design. Engineers must carry professional indemnity insurance, which covers them for any damage they might inadvertently cause to their clients. I’m no lawyer, but that’s how I understand it. The other thing to bear in mind is that construction is usually shades of grey when trying to show fault , and that it’s hard to get clarity on blame. To answer your question though, I wouldn’t expect a refund, I would expect the cost of righting any design errors were addressed.

Sorry to hear about your circumstances. Even if the architect has measured incorrectly (and I’m afraid it probably happens more often than you would think), and even if the builder follows his drawings to the millimetre, the responsibility for any setting out always rests with the contractor. Site sizing always supersedes design drawings. It probably doesn’t help you, but that’s more than likely the legal situation you’ll find yourself.

@@build-better-things hello, thanks for your feed back. In the particular circumstance I referred to we did set out to the utmost accuracy but the idiot architect and he was, believe you me, insisted on the Drawing dimensions as did the ignorant clients, I informed the client that their architect had wrongly dimensioned the existing layout. There had been an extension added at the rear of the property but what the architect hadn't picked up on was that the extension was not set out perpendicular to the existing, he very unwisely assumed it was perpendicular but it was skewed , and it was very obvious to see, don't ask me how he could have missed that fact but the idiot did, there were other structural problems, some very serious that had to be addressed, which only revealed themselves as we did the internal demolition & take down, they were not part of the contract but the client agreed to the Works & they were extensive, including crack stitching, a lot. A Masonry Beam, expensive, as the gable had been so poorly built that it was in danger of collapse, various steel beams, all the window reveals had to be pinned with epoxied stainless steel bar. I don't remember everything we also had to take down the wall between the old part of the property & the "New" extension as it was structurally unsound. Basically the whole property had been built by half wits, they certainly were not professional Builders, we are. We were BBA accredited, sometime back and have always delivered top quality work. But we've had enough of trying to do business in the UK, we've started a business over in the States, where we are is great. Low taxes, no State income tax, although there is Federal Income Tax. The money is many times better and you.get to keep a lot of it. Unlike in the UK. The UK is not business friendly, far from it. We are still in Scotland, doing Trade Work but I'll be moving away next year. And there will be no regrets or tears. The UK is a basket case.

Thanks for your comment and I wish you the best of luck. You can contact me through the links in the channel page if you would like.