The first thing that stands out about Caron’s job isn’t that she found a number of fantastic bargains (though she did find quite a few), or that she used her charm to get Norfolk’s building trade to work for her for next to nothing. No, the remarkable thing is how similar the cost are compared with other houses I have examined over the years. Coincidentally, the last time I did this exercise was also on a house in Norfolk and the breakdown of costs are surprisingly similar. So much so, that there is enough evidence to conclude that a strong pattern emerges — which is good news for those of you wanting to emulate Caron’s experience.

Read more about Caron’s budget self build

Groundworks, Services, Drains

The below-ground work accounted for £13,500 of the overall costs, around 13% of the job total. That’s bang in line with others’ experiences on simple sites where there are no complications.

What could blow the budget? Where the ground conditions are more challenging, you might need to look to an engineered solution, typically using ground piles rather than just pouring concrete into trenches. A difficult site can cost three times as much to get out of the ground.

However, not everything on Caron’s site was as straightforward as the foundations: the site has off-mains drainage and she had to install a sewage treatment plant in the garden at a cost of £2,400. Against this, there was no need for a road connection to a main drain and the very variable cost of this work means that going off mains may often be cash neutral, sometimes even cheaper than making a road connection.

First Fix Carpentry and Roof Cover

The combined total for the first fix carpentry and the roof cover is £16,000, or 15% of the build total. The key here is, once again, simplicity. The main roof uses standard fink trusses; the room-in-the-roof above the garage has a traditional cut roof, which is more expensive to build but has the advantage over fink trusses of providing usable living space within. The carpentry crew worked on the job through the project on both first and second fix. They got paid just over £12,000, of which 40% was first fix and roof carpentry, and 60% was second fix, including staircase, door hanging, kitchen and floor fitting. The roof is covered with a Sandtoft Double Pantile (typical for Norfolk) at a cost of £539/1,000, totalling £1,100. The roofers worked on a fixed price of £2,650. Another £2,000 is in this section to cover scaffolding costs, which could arguably be shared between the brickies and the roofers.

Joinery

This is one area where there can be enormous variations in costs. Caron chose PVCu windows and doors, supplied by Plastic Building Supplies. A total of 16 windows and two doors for just £3,500, or around £100/m². Fitting was an additional £675. Compare this with many joinery systems that cost three times as much and you can see what a budget-buster joinery can be. Caron spent an additional £828 on four Velux rooflights, used in the master bedroom above the garage, and £916 on a double garage door, making an overall total of just over £6,000.

Superstructure Summary

It is interesting to reflect that the combined cost of the groundworks, drainage, brick and blockwork, first fix carpentry, roof, joinery and scaffolding is just under £60,000, or 55% of the overall job total. Again, this is fairly typical of the outcomes seen from other similar projects. Many people assume that the superstructure is the biggest part of the overall budget, but often this is not the case. The internal and external finishes can often amount to rather more, especially if expensive fittings are selected.

Internals

Plastering: the total spend here was just over £6,000, or 5%. This is a little bit cheaper than average, especially as it includes the ground floor screeding as well. The breakdown between labour and materials, 70:30, is very typical: this is a task that is very labour intensive.

Plumbing, Heating and Bathrooms: £9,100, or 8% overall. Again, this is pretty typical. The house is heated by an oil boiler and radiators — no underfloor heating here. It has two bathrooms and a downstairs loo. Much of the sanitaryware was purchased off eBay at some bargain prices. The heating work was all done on a supply-and-fix basis; Caron supplied the bathroom fittings herself.

Electrics: £3,800 or 3%. This was all done under one supply-and-fit contract, although Caron supplied some of the light fittings.

Second Fix Carpentry, Staircase, Downstairs Flooring: £10,400 or 10%. All the materials were sourced by Caron, including a half-landing staircase for £892, internal doors from just £10 each and the ground floor oak-effect flooring for £360, less than £10/m².

Kitchen: £5,400 or 5%, including fitting. Caron sourced the great bulk of the kitchen, including appliances, from B&Q for £3,300. She used the same carpentry crew throughout the job, always working on a price.

Decorating, General and Fittings: £6,200 or 7%. This is a ragbag of costs that includes a woodburning stove mounted in the living room, carpeting upstairs, window blinds, wall tiling, painting the walls and ceilings, and various items like ironmongery, glues and adhesives.

Summary of Internals: £40,900 or 37% of the overall total.

Outside

Landscaping: £6,080 or 6% of the overall total. Included in this total is fencing, turfing, paths and path edgings, a five-bar gate and lots of compacted gravel.

Fees

Professionals: £3,900 or 4%.

  • The surveyor on the job, Graham Sibley, was paid £1,000 for the plans and a further £750 for arranging architects certificates for mortgage purposes
  • Site Insurance was £543
  • Planning Permission £265
  • Building Regulations £838
  • Environment Agency’s Consent to Discharge was £110. This was for a sewage treatment plant

These are very low costs. Design costs, in particular, can be as much as ten times this much and this doesn’t make them bad value, but if you know what you want and it’s fairly simple and straightforward to detail, then it can be a very cheap process. Using an architect’s certificate rather than a structural warranty tends to be a little cheaper, but the cover isn’t so good.

Management: There are no costs indicated in the table because Caron undertook all this herself. Her principal input will, of course, have been her time, several hours a day over a six-month period, probably amounting to around 600-800 hours in total. And there will of course have been other expenses such as extra mileage and heavy mobile phone use. These grouped together would normally be charged as builder’s profit or overheads, or project management fees. Were they to have been charged out professionally, they would typically add 10% to 15% to the basic labour and material costs.

Sweat Equity

Caron was involved in the groundworks and in the first few weeks was to be found at the controls of a digger, but after this she kept her role pretty much to managing the site and clearing up after trades. One of the downsides of employing labouronly subbies is that they don’t see it as their job to keep the site clean. So the responsibility for this falls back on the site manager — in this case Caron.

Breakdown of Caron's Build Costs

Lessons to Learn

  • Keep the design simple
  • Don’t use materials or techniques that the local builders aren’t already familiar with
  • There’s no need to undertake large amounts of DIY — just stick to managing the project
  • But that includes cleaning up after your subbies
  • Get everyone to work on a price — this is easier on simple projects
  • Bargain hard for materials — there are deals to be struck if you have the time and inclination

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