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.
Suggested actions
Before Implementation
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.
During implementation
After implementation
Consider another measurement post-insulation to assess effect. Feedback measured data to add to knowledge of building elements performance.
RELATED MEASURES
FABRIC (13)
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
Secondary glazing
Window Replacement
High performance doors
RELATED REFERENCES (10)
Double Glazing in Listed Buildings – Project Report (2010)
Heath, N
Solid Wall Insulation in Scotland: Exploring barriers, solutions and new approaches (2012)
Changeworks
Tech Paper 9 - Slim-profile double glazing (2010)
Heath, N., Baker, P. and Menzies, G.
Tech Paper 10 - U-values and Traditional Buildings (2011)
Baker, P.
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.
Energy Heritage: A guide to improving energy efficiency in traditional and historic homes (2008)
Changeworks
English Heritage - Research into the Thermal Performance of Brick Walls (2013)
Rhee-Duverne S and Baker P
