Can you tell me...

A. There is no specific definition or information prepared by the CIOB regarding a "warm roof". However, you could contact the British Standards Institution and Building Research Establishment for more information. The following information and sources might provide you with some help and reference.

First, what is the difference between a warm roof and a cold roof? Although these terms are generally used for flat roofs the principles also apply for pitched roofs and the essential difference is the location of the insulation.

A conventional roof is a "cold roof" in that the insulation follows the shape of the occupied rooms so leaving the loft area outside the insulation. The area between the insulation and the roof structure then needs to be ventilated to avoid the build up of condensation. In a warm roof the insulation is placed on top of the roof trusses under the tiles (or other covering). Even though the loft area may be unheated it is now within the insulated "envelope"; condensation is therefore unlikely so there is no need for ventilation. Both types of roof can be well insulated (U-value of 0.2 W/m2K or less is suggested) and neither is more or less efficient than the other. A warm roof will be more flexible if you are planning to convert the loft at a later date (at which point ventilation will be needed as with any other habitable space). If you have no plans to use the loft except for storage then a cold roof will be perfectly suitable.

Source: www.borpin.freeserve.co.uk/sbfaq/faq4037.htm
Websites: www.uwe.ac.uk/fbe/video/covers/regs_vent.htm
or www.fmb.org.uk/publications/masterbuilder/may01/26.asp
Book: Harrison HW (1996) Roofs and Roofing BRE Building Elements, published by Building Research Establishment (ISBN1860810683 & BR 302)

Q. Our client is proposing to use the ECC contract option C (in connection with partnering). I do not know anything about this contract. Could you give me some advice and information.

A. The name of the contract is "The NEC Engineering and Construction Contract (ECC)" and Option C is "Target Contract with Activity Schedule". A partnering contract, between two parties only, is achieved by using a standard NEC contract. The NEC Partnering Option X12 puts the NEC Partnering Option into a contract. This is used for partnering between more than two parties working on the same project or programme of projects.

I suggest you buy the complete box of NEC contracts or at least the following documents:

• The NEC Engineering and Construction Contract (Black Book). This is intended for use as a reference document and contains all the Core Clauses and Optional Clauses
  
• Guidance notes for the NEC Engineering and Construction Contract
  
• ECC Option C: Target Contract with Activity Schedule
  
• The NEC Partnering Option X12.

Q. I am doing a small job (building extension) for about £20,000 to £30,000 and would like to know which contract is appropriate for it and also from where to buy the document.

A. My suggestion is to use any one of the standard forms of the contract for the minor works. For instance use NEC: ECC's Short Contract option or JCT Minor Works Contract, which are used for works of more than £5,000 and perhaps up to £250,000. Both contracts are used for building work and can be ordered from the CIOB.

Q. What partnering contract, if any, would be recommended and what protocols represent best practice?

A. Currently, there are some partnering related contracts, however I recommend NEC Engineering and Construction Contract and PPC 2000 forms of contract.

With regards to best value and partnering, there is good information prepared by the Construction Best Practice Programme.

Website: www.cbpp.org.uk/cbpp/themes/pt.jsp