ICF and balconies..

[MariaD]

I have a rectangular house design, measuring 10.9m x 7.3m externally (10.3m x 6.7m internally), with the ridge of the roof running parallel to the longest side. The building is a two-storey structure, plus an attic.

My question is this: Keeping in mind that the frame will be built using Insulated Concrete Forms (ICF), would it be possible to add a balcony similar to the one in the picture below (with the roof extended to cover the balcony) ? The balcony would be approximately 1.8m deep and 10.9m long, running the entire length of the house.

What would be the best method to construct the balcony?

If you were to estimate, how much additional cost would the balcony incur? Please consider that adding the balcony would likely increase the size of both the roof and the foundation.

 

[JohnMo]

Ask your structural engineer, he would have to approve it anyway.

 

Cost really changes hugely depending on who does the work and what finish you need to achieve and wind loading. And how you purchase materials. Same decking boards can be 3x the price from a local building merchant compared to online.

 

Mine sits on a concrete block ledge which is part of the foundation and 225mm x 45 wooden structure anchored to the ledge.  Outboard of that is a series of concrete pads with steel upstands to which the wooden framework is attached. 

 

Some photos, you would need to project upwards also.

 

 

 

 

[ChrisJ]

Is your balcony proposed to be concrete or wood? Both are possible, personally I’d do concrete for long term. Based on your picture with columns from foundation to underside of roof this will all be quite simple for the engineer to design connection and support details 

 

price - you’ll need design first and then go for pricing 

[Conor]

Ours is steel frame, cut through insualtion and bolted to the ICF. Support columns and walls. It's not a cheap exercise at all. Ours is 2 x 12m, L shaped. The steel along was £3k. Timber deck another grand. GRP , £1k. Paving pedestal, pavers, glass ballistrading, another £8k. Supporting walls hard to cost up but another £2k. Mostly DIY except the walls. The reason we went with a fully tanked design was to create shelter in the main patio below. You could do it with softwood timber for about £3k. I'd allow £15k for yours if you want it to the same spec and to be professionally built. Not allowing for roof etc. that could double it.

Edited April 23 by Conor

[Mr Punter]

At a guess I think about £60,000 plus fees, so budget £70,000, which would include everything assuming it is carried out by a main contractor with the rest of the build.

 

I have sometimes found proper well finished balconies are more expensive per m2 than internal space.

[MariaD]

On 23/04/2024 at 19:28, Conor said:

Ours is steel frame, cut through insualtion and bolted to the ICF. Support columns and walls. It's not a cheap exercise at all. Ours is 2 x 12m, L shaped. The steel along was £3k. Timber deck another grand. GRP , £1k. Paving pedestal, pavers, glass ballistrading, another £8k. Supporting walls hard to cost up but another £2k. Mostly DIY except the walls. The reason we went with a fully tanked design was to create shelter in the main patio below. You could do it with softwood timber for about £3k. I'd allow £15k for yours if you want it to the same spec and to be professionally built. Not allowing for roof etc. that could double it.

Thank you for the comprehensive explanation.

Frankly, the expense appears to be a bit daunting. I hadn’t anticipated such a high cost.

 

I also had the intention of utilizing the balcony to provide cover for the patio area and to offer shade during the summer. It appeared to be the most effective solution to me, but the expenses seem to be prohibitive