CAERPHILLY county borough council is failing to hit its targets for building affordable homes, a report has revealed.

The authority had set a target of building 964 homes through its planning system, including funding from section 106 agreements with developers, by 2021.

But only 251 affordable units have been built since the local development plan (LDP) was adopted in 2010 – less than a third of the overall target. And 96 of the completed homes were built before the LDP came into force.

The closest planners came to building 85 houses per year was 52 completions in 2015/16. In 2012/13, only 10 units were delivered.

Since 2011/12, the council have secured permission for 498 units through section 106 agreements.

Planners have also received £146,240 in commuted sums from developers who were unable to provide affordable housing on agreed sites.

These funds can be used to secure affordable housing provisions on newly identified sites in the county borough.

A report set to go before the policy and resources committee said there were “multiple reasons” for why delivery has been lower than expected.

“Clearly, the decline in housebuilding as a result of the economic crash and recession resulted in a significant drop in housing completions compared to pre-2008 levels,” it reads.

“Furthermore, the decrease in house prices in the years immediately after the crash as a result has had an impact on the viability of schemes. Average house prices in Caerphilly County Borough have only returned to the 2008 levels in the last year.”

Affordable homes delivered by the council only account for a small portion of its overall target of 3,664 units by 2021, with registered social landlords (RSLs) developing their own housing schemes.

Successful RSL developments include the 82-home Beeches Village community on the site of the Caerphilly Miners’ hospital, the former Manor Inn in Ty Sign, Risca, and at Bridge Street in Abercarn.

The report said that council affordable housing schemes in Lower Islwyn, Newbridge and Aber Valley had been secured but “none of these sites have been delivered by the private sector”.

Figures from the joint housing land availability study (JHLAS) show that 918 units built by the council and RSLs had been delivered up to 2016.

But the Welsh Government Affordable Housing Return says that 1,518 affordable units have been built in Caerphilly county borough – less than half of the overall target. The findings include new-build schemes as well as the purchasing, leasing and conversions of existing units, which would not be included in the JHLAS.

The full report on affordable homes in new developments will be scrutinised by councillors at a meeting on Tuesday April 10.