Step 2 dig a hole, fill it with concrete

There are a whole bunch of possible ways when it comes to building a foundation.

Most of them start with digging a trench and filling it with concrete. If your building needs to comply with building regulations you’re best off agreeing the depth with them. They will take into account things like tree roots, types of soil, etc…

Although the studio did not need to be subject to building regs we were building an extension nearby that was. During one of their visits the regs officer was kind enough to give us some advice on the studio footings too.

The studio (at the time) was close to a bunch of Leylandii ‘trees’. For those who don’t know, Leylandii are bastards. They grow about 1 meter per year even in naff soil. These ones were massive. I have since got fed up with them and went at them with a saw, there’s now a nice fence there instead.

As a result of the trees, the Regulations Inspector suggested that we either go for deep foundations or consider going for a solid, steel reinforced concrete base.

I went for the Steel reinforced concrete base. Looking back, I have reservations about this which I will highlight below. Either way, the ‘method’ for this kind of base is as follows:

  1. We dug out the floor of the studio 200mm deeper than it would be when we were finished.
  2. We dug a trench around the outside just over half a metre deeper than the floor.
  3. We lay 100mm Celotex insulation board so it was to go beneath the floor.
  4. We covered the insulation and bottom of the trench with polythene membrane.
  5. We set up a steel mesh over the floor and going down into the trenches.
  6. We poured a hell of a lot of concrete into the hole until it was floor level. This step is shown in the picture below, apologies for the state of my phone camera.

2012-03-23 16.14.56

Costs

I’m not sure of the exact costs as we were also pouring a footing for some decking and a wall running up to the studio at the same time. But the total bill for the pouring phase came to just under £600 for the materials, £250 for the concrete pump and about the same again for labour. Total: ~ £1,100 for the pour.

Other items involved in the footings project were the insulation (about ~£40 for a 1.2m x 2.4m board) Digger Hire and skips for the excess dirt. In my case I’ve used much of the clay that we dug out of the footings for a garden landscaping project, this has saved a fortune in skips.

Total bill for the footings I would estimate at around £2000. You would need to allow for more for skips if you didn’t have a landscaping project in mind for all the soil you pull out.

Learning the hard way

Looking back, my choice of single pour solid base may be the start of my first mistake with the studio. I’m not sure if it was a certain thing then, but I have ended up with a wood beam floor in the studio. The wooden floor is supported by beams above the concrete base with an air gap between for ventilation.

This floor has the potential to resonate like a drum and will be a constant pain going forward.

I am where I am now and I can’t afford to change this. But I would recommend anyone else at this step stop to research and ask if there are alternatives to this configuration either available with the solid, single pour base or by going with a different kind of footing. I would be much happier if I could stand directly on the concrete base.

Step 1 Getting permission

No matter what country you are in there will be laws about what you can build and where.

Because I am building this in the UK on part of the same plot as an existing house I can use certain building rights called permitted development. Please note that this post is just my take on the rules and that if you are in doubt you should go to your local planning office and ask for their advice, my experience was that they were very helpful.

There are 2 ‘impediments’ to just building what you like in the UK: Planning permission and Building Regulations. Permitted development takes care of the planning permission aspect for quite a few extensions and outbuildings.

The government planning portal site provides some quite useful interactive graphics on what is allowed for extensions and outbuildings.

I doubt when this was debated in the house of commons the MPs were thinking about music studios, so the precise rules I am using generally refer to outbuildings like sheds and summerhouses.

More details for outbuildings are available here. However the basics are that, since I’ve not covered 50% of my garden even with the studio, I am free to build an outbuilding. Further I am not subject to building regulations providing it is either less than 15 sq m  or between 15 and 30 sq m and made out of ‘substantially non-combustible materials’. The only exception to this is the electrics which I will have to get signed off.

I figure that bricks and concrete count as non-combustible, and my studio works out to be a tad under 28 sq m.

As it happens, the chap doing most of the structural work for me is helping me keep it to regulations anyway. There have been a few times that this has lead to less than ideal acoustics (the damn wood beam floor is basically a big resonant cavity) , but I think keeping the building inspectors happy is probably better than to risk having to tear it down. TBH, the building inspectors have been very approachable even offering some advice on the studio when they had come round to review some work I’d done extending the house.

I should add that there was a 3rd even more important party that needed to approve of what I was doing – Kate, my very patient wife.

I also get the feeling that the bass drum should get a mention as an inanimate ambassador in all of this. By not fitting through the loft hatch, he resolutely took up storage in what is going to be the downstairs bathroom, thus re-prioritising the studio.

High five, Ambassador Bass drum.