With your Self Build Office all set up (in a cupboard under the stairs/on the bookcase in the dining room/in the spare bedroom of the "temporary caravan"), the paperwork's all done; plans of your new home are pinned to the door or wall beside the year planner with write on wipe off pen dangling on a string and ready for action; the insurances are all paid up and the building control organisation has been paid up front - what comes next?
It is helpful to think that the area where you are going to build your new home needs to be a clean sheet of paper, similar to that you faced months (or even years) ago when you first started sketching your home designs. If you used a previously scribbled on piece of paper then, your new lines would have been totally confused and brilliant ideas may have been lost. If you try to set out the real thing in a messy environment, you will spend more money than you need to pouring concrete into trenches that you put in the wrong place.
So. Clear your site. Remove all rubbish and unnecessary detritis before you do anything at all.
If you have purchased your site and it has conditions that you fence off boundaries, please give serious consideration to doing these how you want them to always look right away. If you put in a temporary fix and postpone the fencing, wall or trees until the end of your build you
You may have planning conditions regarding access or land contamination - or any number of other things. Without doubt, they will all have to be dealt with before you dig a single trench. However painful (in terms of waste of time/energy/money) you have no alternative but to get them done. Bite the bullet - act positively.
With rubbish removed, physicaly boundaries built and planning conditions met - you need to get the tape measure out. Using the measurements on your plans which tie your build to the boundary, mark out the position of each of the corners of your build. This is jolly exciting as it is the first time you get to walk around your new home! Next, add at least 2m to the perimeter of the build (where space permits) and mark this as your Building Space. You need this much space clear of obstructions at it will be covered by your house and the scaffolding for many weeks to come. The more space you can give your build and the cleaner you can keep it will all prove beneficial in the long run.
Every site is different but most of them need to have the topsoil removed from at least the house footprint plus the aforementioned couple of metres and associated driveways . This could mean removing many tonnes of soil and on small sites, this adds considerably to the cost of Groundworks as it will all need to be shipped out. It's not possible to give an average price for this as land varies so much, but if you remove 150mm of topsoil from a 100 square metres area, you will be moving 15 cubic metres of soil which has several paymasters - the JCB driver, the tipper truck to take it away and the Government for Land Fill Tax.
With reference to my "contamination" mention in the Planning Conditions above, if you live in a mining area, after you have paid a consultant for a report, you may well be removing the topsoil and 500mm of subsoil from your garden area before you lay 100mm of stones, a layer of membrane and fill it all up again with certified clean topsoil. Do not underestimate these costs - they can be heinous.
Every load bearing elements of your house must have a foundation under it. Think external walls, internal load bearing, chimney breast, party wall. Setting out for the foundations can be done by anyone who understands trigonometry, can accurately use a tape measure and is confident and competant enough to give it a go. Otherwise, ask your builder.
On average it will take two chaps a day to set out a detached house. There are very little other costs involved - a few lengths of 2x1, some string, some colourful spray and the hire cost for a laser level. Setting out needs to be accurate though as mistakes are expensive as I mentioned before. Ask any craftsman and they'll say - measure twice, cut once. In the case of your foundations, practice this then practice it again!
The perimeter of a "standard" house is likely to have 600mm wide footings with internal load bearing walls possibly only requiring 450mm. The determining factor for the width of the footings lies with the width of your finished walls. Each side of the foundation must protrude beyond the wall by 50% of its width. So a 300mm thick wall has foundations of 150mm + 300mm + 150mm = 600mm. The trenches should then be in the order of 1m deep (although this does depend upon ground conditions and the site and they could be deeper or shallower). Other than soil conditions a driver of depth is our weather - or frost more precisely. The top block of the foundations must be at least 150mm from the finished ground levelAll the soil dug from the trenches needs relocating to elsewhere on your property, or transporting off site. So you begin to see why groundworks eat up so much of your budget.
Once your trenches are complete, it is time to invite your Building Control Officer for his/her first visit. As mentioned before, get to know this person. Once they understand that you are building by the book and not taking silly shortcuts, they will be very pleasant to deal with. If you think you can "get one over", they will be officious - and rightly so.
Timber Frame - Design & Build
Holmbush Woods, Stoke Road
Kelly Bray, Callington
T: 01579 388800
19 & 20 June 2021
Look forward to seeing you there and discussing your plans
Usually, we would be delighted to welcome you to our offices to enjoy a cuppa whilst we discuss your aspirations - for now, the phone or email will just have to do.
Monday - Friday 8.30-5pm
Please see the Covid 19 page for latest update