New attic, what costs arise?

Especially with old houses renewal of the roof truss is often beneficial several times. A damaged attic, which is being redesigned, often offers more space under the roof than the old one. What costs you have to expect for a new roof structure, and what the cost of a roof truss depend, you will find in detail in this post.

prime example

As an example we want to have a Pfettendachstuhl newly built on our family house. It should be simple, planned later is a pitched roof with a roof area of ​​180 m². Due to the comparatively large depth of the house (10 m width at 12 m length), we can not construct a rafter roof, but require a purlin roof.

total price10,040 EUR
material4111 EUR
working hoursabout 132 hours

Tips

Details about our roof truss and the work carried out can be found in this service description.

All prices in the article are net prices.

Note

Note that the given price example is a single example of a Pfettendachstuhl, as we have planned for a specific house. The cost of other roof trusses, especially other types of roof trusses, can be very different for the same size. Decisive for the price is always the individual planning of the roof shape and the static conditions of your very special building.

Not considered works

In this example, we did not take into account the demolition of the old roof truss (the costs can be found under "Costs for additional work required"). Also, all subsequent work, such as the battens of the roof truss are not considered here.

General

Trusses can be constructed in very different ways. This also affects the price. There are also different roof shapes for which a roof truss forms the support frame. There are two categories:

Roof construction:

  • Rafter roof (simplest form of construction, inflexible, not suitable for very deep buildings)
  • Purlin roof (universal roof shape, also allows easy installation of dormers, offset rafter layers possible)
  • Kehlbalkendach (special form of the rafter roof, larger widths can be bridged)

Roof shape:

  • saddle roof
  • Hipped roof or cripple whale roof
  • mansard roof
  • Pent roof

The exact structure of the roof truss always depends on the desired roof type and the static conditions for this roof. Thus, the price of a roof truss for each roof is different, depending on the static requirements.

Basic price criteria for the roof truss

Dachstuhlart

In our example, a simple purlin roof chair was constructed. This results in around 45 - 65 EUR per m² of roof area, if the wood consumption is equal (with 0.06 m³ per m² of roof area) and the same snow load zone (in this case 1a) is required.

The differences between the roof truss types can be seen here:

Dachstuhlartprice
Pfettendachstuhl50 - 70 EUR per m²
Rafter roof52 - 72 EUR per m²
Collar beam roof52 - 72 EUR per m²

wood consumption

The previous table is not only informative insofar as, depending on the construction method of the roof truss, the wood consumption per m² naturally changes. He is the actual price-determining size.

With a wood consumption of 0.06 m³ / m², our purlin roof chair costs between 50 and 70 EUR per m² of roof area. If the wood consumption increased to 0.08 m² / m³, the price for the roof truss would already be much higher - namely between 64 and 92 EUR per m² roof area. The wood consumption of the attic usually ranges between a minimum of 0.04 m³ / m² and a maximum of 0.15 m³ / m². The value of the wood consumption for the roof truss results from the construction method and the static requirements, as well as from the planned roof shape. It can be determined during planning.

Snow load zone

The snow load zone is an important criterion in the construction of trusses. Depending on the geographic location of a structure and the topographic altitude in which it is located. The standardized snow load must be included in the static calculations for the roof truss. Higher snow load zones mean that the roof truss needs to be made more stable, which increases its price. In Germany one often finds the zones 1 and 2, in the Alpine areas also the zone 3. The zones 1a and 2a apply predominantly to the Hochschwarzwald, the Sauerland and the Rhön area. The price of the roof truss can therefore vary significantly even in completely the same buildings in different location or altitude.

Cost of possibly additional work required

Demolition of the old roof truss

The cost of demolishing the old truss is usually calculated by the contractor by tonnage. Decisive is not the roof area or the type of roof truss, but the weight of the wooden structure. If there are no restrictions and devices can be used for demolition, the cost of demolition is around 110 - 150 EUR per tonne.

difficultyapproximate additional costs
No use of equipment possible+ 150 - 170 EUR per ton
Low-noise and low-dust design+ 5 - 7 EUR per ton
Heights over 4.5 m (up to 10 m)+ 30 - 40 EUR per ton

For the conversion of the m³ value of wood into tons, the so-called "weight", the specific weight of the wood is needed. For most trusses, it is possible to assume a density of 7.5 kN / m³, but this can be different.

Conservative factors

  • simple roof shape
  • low roof pitch (very low wood consumption at the purlin roof)
  • simple design of the roof truss
  • low payloads

Increasing factors

  • high required loads on the roof truss
  • Planned coverings with a high basis weight (for example concrete roof tiles)
  • high roof pitches
  • complicated roof shapes

Saving opportunities through self-construction or personal contribution

A roof truss requires solid carpentry, and setting up not only requires multiple people and equipment, but also a great deal of expertise and experience. If necessary, however, in individual cases you can - provided appropriate sweets and expert knowledge - provide their own services in consultation with the carpenter's company. Whether and what cost savings that brings, then depends on the arrangements made. In most cases, the operation will probably refuse.

promotion

As the erection of the roof truss or renewal of the roof truss is not a measure in the field of energetic refurbishment per se, this service is usually not granted any support, but of course whenever the renewal of the truss is carried out as part of a refurbishment or energetic improvement happens. You will find more information about possible subsidies and write-off options in our general funding overview.

Tips & Tricks

If you choose a lighter cover, the load on the roof truss does not need to be so high. You can then often save considerably on the attic. Lightweight coverings are, for example, plastic roof panels or fiber cement panels, concrete roof tiles have a particularly high basis weight.

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