The land where the house will be built is made of clay (savimaa - old bottom of the sea) and therefore the foundation has to be made on pillars (7-10m long) that are standing on the firmer ground beyond the clay. Then on top of the pillars will be put hollow core floor beams of 26.5cm thick. Then insulating material 25 cm (
Expanded polystyrene (EPS)) and a concrete floor of 8-10 cm thick into which also the floor heating pipes will be installed. Below is a picture I've taken of the way it sort of looks although our insulation is bigger than in the picture where I guess is only 20cm and the side plinth beam will be from solid concrete.
The technical drawing for our foundation wall structure looks like below (there's crawling space under the floor of at least 0.8m):
The foundation is not coming from Lapponia house so we had to get the whole package from another company.
We had asked quite a few companies for quotations but not many offer ther complete package ( pillars, beams, insulation, concrete floor casting, etc). We got basically offers from 2 companies for the complete package: Basso (via Lapponia sales agent) and Me-Perustukset. The initial Basso offer was 50 % (!) more expensive than the one from Me-perustukset. Only after Basso found out the fact that we got a much cheaper offer from ME, Basso also came down to a much similar price. But then we did not want to consider their offer anymore as we felt Basso initially tried to ripp us off. Also Basso's offer did not include making the ventilation holes and also it requires to pay separately if the foundation/ concrete needs heating during the colder season.
The round prices of the offer we accepted from Me-perustukset for our foundation and pillars (materials and installation) including the terace were:
- plinth beams and floor beams (sokkelipalkki ja ontelolaatta) - 18000
- steel pillars (teräspaalutus) 112m - 4500
- concrete floor casting - 3000
- steel net and EPS insulation - 2700
- foundation and water drainage design - 1200
So far I have been happy with the service from Me-perustukset and the sales person speaks very well english (Mikko Kuoppa -
Update Nov 2011 - Mikko left the company we were told).
Even more of a pleasant surprise was that the during the design fase, the Me-perustukset planner came with a proposal for a different set up of the foundation which needed less plinth beams and steel pillars than were quoted in the initial offer and therefore we got a reduction of 2000 euro in the total price!
See also our other post about foundation:
http://project-eco-house-finland.blogspot.com/2011/04/week-16-foundation-is-fast-and-furious.html
UPDATE Nov 2011:
We concluded not to recommend anymore ME-perustukset due to the fact that they have been delaying our garage foundation for very long during the summer and the contact person from ME was saying many times that they come next week, and then next week etc. And when they came they have made the garage pillars too weak. Our head-designer / vastaava meestari asked them to correct it and after couple more weeks they came and made the pillars again but then once again they were wrong (not fulfilling the standards). ME-perustukset contact person mentioned that the garage foundation was being made by a subcontractor of theirs but that does excuse them, I would say. The third time went right, after our head-designer explained them on the spot what went wrong.
Now, due to delays and frost coming up, we decided to postpone the finalization of the foundation until next spring...