Green Building Forum - What construction method to use?

What construction method to use?

PaulJ — Tue, 05 Feb 2013 17:23:58 +0000

The project is for a terrace of seven houses in Sussex , next to the river. As part of the works we will carry out improvements to the river wall. The ground floor needs to be flood resilient, so will probably be blockwork / steel but I would consider another method for upper floors.

Elevations are finished in natural slate and painted (Cedral?) weatherboard. Roof is natural slate with flat roof terraces to 3 units. Target u values are walls 0.15, roof and floors 0.13. There are lots of awkward junctions / balconies / terraces to consider. They need to be NHBC compliant. The foundations will be piled â€“ probably with a raft.

What do you think is the best construction method for the buildings?

What construction method to use?

PaulJ — Tue, 05 Feb 2013 17:24:38 +0000

and the back...

What construction method to use?

DarylP — Tue, 05 Feb 2013 17:25:43 +0000

....how high from the 'normal' river level?

What construction method to use?

PaulJ — Tue, 05 Feb 2013 17:35:37 +0000

The river is tidal. Low tide shown in pic. High tide can bee seen from the green on the adjacent buildings.

What construction method to use?

Triassic — Tue, 05 Feb 2013 17:48:01 +0000

How about a steel portal frame structure for the flood-prone ground floor level, with infill block work clad in weather board to match the rest of the building.

Next I'd design a timber frame passive house home to sit on top of the steel frame, whilst at the same time eliminate the awkward junctions.

You could go for steel free-standing balconies, so as to eliminate cold bridging with the passive house.

What construction method to use?

PaulJ — Tue, 05 Feb 2013 18:36:07 +0000

Posted By: TriassicHow about a steel portal frame structure for the flood-prone ground floor level, with infill block work clad in weather board to match the rest of the building.

Sounds sensible. Do you have any suggestions for how we insulate - internal / external / cavity?

Next I'd design a timber frame passive house home to sit on top of the steel frame, whilst at the same time eliminate the awkward junctions.

I have done a few houses with timber frame so I am fairly comfortable with this. I have never attempted a passive house, but if it could be achieved with little additional cost I would consider it.
Again, placing the right insulation in the right area, plus dealing with the junction with the floor below will be crucial. Also, with timber frame I would want to be extra sure to reduce fire risk.

You could go for steel free-standing balconies, so as to eliminate cold bridging with the passive house.

Yes, I have done bolt-on steel balconies with timber frame before. They are a pain when they have terraces - going into the building - as the floor / downstairs ceiling needs insulating.

What construction method to use?

Triassic — Tue, 05 Feb 2013 20:08:32 +0000

If the ground floor is susceptible to flooding maybe best not to worry too much about insulation, keep the space for car parking, storage, play rooms etc.

For the ground floor steel structure, If it were me Iâ€™d go for infill block work with external insulation, finished in waterproof render. If the steel structure were capped off with a concrete 1st floor this would provide a fire barrier between the garages and the house, and give a solid foundation off which to construct the passive house.

If you want to look at various construction options why not look at www.viking-house.co.uk/ and click on the â€œconstruction methodsâ€ link or Google â€œPassive House constructionâ€. My understanding is that passive house construction methods should only add 5% to the total cost. Others here may have more information.