31a, Armitage Way, Cambridge, CB4 2UE

31a is a detached house in Cambridge (CB4 2UE). It has a recorded floor area of 24 m² (around 258 sq ft), construction records dating it to 1983-1990 and council tax band A. The latest certificate (May 2020) shows a D (score 63), on the cusp of jumping into the C band. When first surveyed in January 2009 the rating was E, the property has climbed 1 band since. Between certificates, wall efficiency went from Average to Good, lighting went from Poor to Very Good and main heating went from Poor to Average; while hot-water efficiency dropped from Poor to Very Poor. The recommended improvements would push it to C (score 69). Main heating runs on electricity. At 24 m² this is the 5th smallest of 40 units on EPC record in the building, where floor areas span 21–139 m². The building's EPC ratings span E to B across 40 units on file.

At 24 m² it sits well below the postcode median (50 m² across 39 EPCs), making it one of the more compact homes locally. On the market in June 2016 and unlisted since — roughly 10 years. Across the public record there are 4 sales, relatively high churn for a single property. Across 1999–2016, sale prices on this property compounded at 8.6% per year. On a £-per-square-foot basis, the last sale (£561/sq ft) was about 162.5% above the typical sold price in the postcode.