Concern & action: Actual U-value?
Performance gap between the modelled U value for any building element and its actual thermal performance can be considerable. Inaccurate modelling can lead to incorrect specification of measures and unexpected energy use outcomes.
Physically measure U-value or conductivity of fabric elements (e.g. walls) prior to determining insulation strategy. Consult tables of measured in situ U-values for similar wall constructions of similar thickness. Consider adjustment to overall refurbishment strategy if measured U-values are found to be significantly better than the calculated U-values to those quoted in official literature.
Consider another measurement post-insulation to assess effect. Feedback measured data to add to knowledge of building elements performance.
External Wall insulation
Internal Wall insulation
Frame infill insulation
Floor insulation between/under floor joists
Floor Insulation on top of existing floor finish
Floor void filled with insulation
Exposed soffits to upper floors: Insulation in between joists or under soffit
Replacement of existing ground floor with new concrete insulated solid ground floor
Energy efficient glazing
High performance doors
RELATED REFERENCES (10)
Tech Paper 9 - Slim-profile double glazing (2010)
Heath, N., Baker, P. and Menzies, G.
The SPAB Research Report 1: The U-value Report. Revised 2012 (2012)
Rye, C. and Scott, C.
The Performance of Traditional Buildings: the SPAB Building Performance Survey 2013 (2013)
Rye, C, Scott C & Hubbard, D.
English Heritage - Research into the Thermal Performance of Brick Walls (2013)
Rhee-Duverne S and Baker P