Low or zero carbon technologies

8.2.9Building integration

LZC technologies shall be securely fixed and not adversely affect the weather resistance of the building.

Foundations and anchor points for stand-alone LZC technologies should be designed by an engineer in accordance with Technical Requirement R5 to withstand the structural forces acting upon them.

The structure to which the LZC technology is attached should be assessed according to its ability to accept the loadings and prevent detrimental effects arising from movement or vibration. The design of the structure should take account of:

  • the self-weight of the LZC components
  • imposed loads
  • wind loads
  • snow loads
  • dynamic loading (where relevant).

Notching, drilling or chasing of structural components to accommodate service pipes or cables should either comply with Chapter 8.1 ‘Internal services’, or be designed by an engineer in accordance with Technical Requirement R5.

Fixings, supports, bracketry and mounting frames should:

  • accommodate all static and dynamic loads in accordance with the manufacturer’s recommendations
  • be designed to take account of ventilation and drainage requirements of the LZC technology
  • have adequate protection against corrosion.

Where two metals are to be joined, they should either be compatible or isolated, to prevent bimetallic corrosion. Aluminium and aluminium alloys should not come into contact with cementitious material.

All interfaces between the LZC technology and the building should ensure adequate weather resistance, sealed to limit air leakage and prevent moisture from reaching the interior or any part of the structure that could be adversely affected by its presence. The envelope should be weatherproofed using appropriate flashings and fixings. Weatherproofing details that rely solely on sealant are not acceptable. Flashings should be formed from the materials listed in Table 1.

Table 1: Materials for flashings

Flashing materialGuidance
Rolled lead sheetMinimum code 4. BS EN 12588.
Aluminium and aluminium alloysBS EN 485 and BS EN 573, 0.6-0.9mm thick and protected from contact with mortar by a coating of bituminous paint.
Zinc alloysBS EN 988 and 0.6mm thick.
CopperBS EN 1172 0.55mm thick and fully annealed. Where two metals are to be joined, they should be compatible and not cause bimetallic corrosion in that environment Alternatively, they should be isolated from each other.
Proprietary flashing,
including plastic and composite.
Assessed in accordance with Technical Requirement R3.

To avoid potential surface or interstitial condensation, the design should take account of thermal bridging, particularly where any part of the system, including fixings, penetrates the thermal envelope.