More than a shade of difference | Features

Specification options
External solar shading louvres	Capital cost £/m	Net present value for 60 years £/m
Aluminium areofoil sections, fixed, 1.2m projection
Mill finished	220	400
Polyester powder coated to BS 6496, minimum 40 microns thick	270	600
Polyvinylidene fluoride (PVDF or PVF2) minimum 25 microns thick	320	690
Anodised BS 3987, minimum 25 microns thick	250	480
Aluminium slat sections, fixed, 1.2m projection
Polyester powder-coated to BS 6496, minimum 40 microns thick	180	450
Aluminium louvre system adjustable with polyester powder-coated to BS 6496
Manually adjustable with crank	370	990
Motorised adjustment	595	1,650
A discount rate of 3.5% is used to calculate net present values. Extruded aluminium to EN 755. Period to first maintenance dependant on colour of finish and exposure to pollutants and solar radiation. In practice, it may be more economical to replace solar shading rather than remove and recoat, or carry out insitu redecoration. An alternative strategy may incorporate solar shading replacement, or redecoration, with a major facade refurbishment. Life-cycle costs include servicing, inspection, cleaning, allowance for repairs and replacement at period to first maintenance (upper values used in the table).BLP provides latent defect warranties for buildings www.blpinsurance.com. For durability information contact: peter.mayer@blpinsurance.com or call 020-7204 2450.