Drivers of performance

A key driver of the increase in our net assets is the underlying performance of our investment portfolio, which includes our share of joint ventures (see Table 6).

The positive valuation surplus on our investment portfolio was wholly attributable to the success of our development programme in that the valuation surplus on the development programme of £174.2m exceeded the surplus on our overall investment portfolio at £130.8m.

On the like-for-like portfolio which excludes developments and acquisitions and so allows for performance comparison of income growth and yield change over time, there was a small valuation deficit for the six months of £37.8m or 0.4%. As expected there has been a re-pricing of property investments which has seen yields rise and capital values fall. This re-pricing would in itself have decreased capital values on our like-for-like portfolio by some 4.6%, but it was largely offset by continuing rental value growth of 4.6% over the six month period.