Building another storey on top of a bungalow

Our experience is that a knock down and rebuild is the cheapest option. We are three months into our build which sounds similar to yours. We started out planning to add a first floor to an existing bugalow in a rural location. Build costs for the addition of the first floor and amendment to the floor plan were quoted at the same costs as we are going to end up with for a complete knock down and rebuild. We are hoping to bring the cost in at around £315-325K for a 250 sqm property (150m ground floor, 100m first floor) which is around £1,300/m and includes UFH, GSHP, softwood factory finished windows, oak internal and front door, 1 ground floor wet room, master bathroom and ensuite to first floor and four large bedrooms, a huge amount of glass including two bifold opening doors to the family room and master bedroom, with a mid to high level finish spec.

The saving being that we are vat free instead of adding a further 15% (17.5% soon). Costs are for fully finished property (decorated and ready to move in) with only minimal input from ourselves on site, so far two days! The build is being managed by our Builder and he is contracting in roofers, electricians, etc, but is doing a huge amount of work himself. If the spec was lowered, I feel that we would be looking at a total cost of around £275-290K

First Selfbuild, knocking down and rebuilding an Old Vinery using the original foot print and roof pitches as reminder of the buildings history.

Hi Ian

Just had a look at your blog, very interesting, particularly the demolition because we'll need to do the same before we can build. Would you mind sharing how much it cost for the demolition and what they actually did.

Many thanks

John

We are currently developing the first storey on our 1950's extended bungalow using Sip’s panels. The external footprint measures 150 sq metres. The existing ground floor has been gutted, the internal space re-arranged and re-plastered, re-wired and re-plumbed.

Unlike your project we are restricted from raising the overall height and changing the property into a house but we hoped with Sips to avoid too many internal supports inside the roof and gain enough extra space for our needs. We also thought it might be lighter in weight which was a consideration what with using the old existing bungalow walls.

The cost element for the whole of the new Sips roof, some external Sips walls approx just 1.1m in height and all the internal stud walling to create two bedrooms with ensuites, the kitchen, dining and sitting room is costing £34k including installation. This price rose from the initial quote of £20k when the company's structural engineer became involved in the design. We were originally intending to construct our own stud walling using traditional methods after the roof installation but it was advised they should be constructed with Sips so additional support could be included.

We have had to create an entire new strengthened floor platform from which the new panels can be installed; we have done this ourselves on a mainly diy basis. With Sips it is essential that levels are within 20mm overall which we have learnt to our cost. I believe timber frame is a bit more forgiving. Also, any hope of reducing the weight has proved impossible, massive steel work is being incorporated, way above requirements in our opinion and that of our own structural advisor. However, we have felt obliged to provide what they are asking for to get on with the build due to the cost of delays.

We have had a fully weatherproof scaffold erected over the property since August and due to delays on both sides this is bumping up costs. The installation was due to start at the beginning of Dec but hopefully will now be happening in the New Year. Our hope of it being a fast process doesn't seem to apply to the drawing and design preparation, we were advised about 7 weeks in total, its been about 3 months in preparation before panel manufacture.

We have wondered whether it would have been much dearer to demolish and start from scratch, I don't think there would have been much difference in price in the end, it has been harder to incorporate more new structural support elements required for the Sips steelwork in an existing building especially since we were knocking down some load bearing walls to create an open plan layout in the ground floor area.

Hope that's been of some help. All the best with your plans.

My sister has just added another lift to her bungalow. It was timber framed and I must say it looks great. I can't seem to get the permission here in Surrey for some reason.