Councillors have granted planning permission for 70 new homes to be built on a field beside Keynsham nature reserve "through gritted teeth".

These are the words from one councillor, after the developer made improvements to the scheme's impact on biodiversity and transport.

The plans had attracted 265 objections and only two supporting comments. It was originally sent back to developer Taylor Wimpey by Bath and North East Somerset Council's planning committee over concerns about biodiversity.

However, revised plans addressing these concerns have now been submitted and councillor Duncan Hounsell warned the planning committee that they could face an expensive appeal if they rejected them without "rock solid" reasons.

He said: "Planning is not decided by the number of objections or the number of people in support. It has to be judged on planning policy and emerging planning policy."

The houses will be built on a field between the Manor Road Community Woodland nature reserve and Minsmere Road. 30% of the houses will be affordable housing and, following revisions made by Taylor Wimpey's consultants, the site will also feature "bea bricks," insect hotels, and 40 bat boxes, as well as information boards about ecology in the Manor Road nature reserve.

Developments in Bath and North East Somerset must show that they will lead to an overall increase in biodiversity before they can receive planning permission. The developers had originally proposed fulfilling this requirement by investing in biodiversity in another nearby location which, although permitted under the rules, did not satisfy councillors.

Despite the additional biodiversity measures on site, most of the development's biodiversity gain will take place on this separate site.

The planning committee voted to approve the plans although some councillors voiced their reluctance. 

Westfield councillor Dr Eleanor Jackson said: "I am going to vote for it through gritted teeth because […] I am not entirely convinced about the biodiversity net gain and the way that's going to be accomplished."

Hal McFie, councillor for Keynsham East, voted against the plans as he was unconvinced about the amount of green space on the site and felt that the biodiversity gain should be on the site of the main development.

He said: "When you make a development we actually don't want the diversity to go down. We want the diversity that you've got, that you are living among, to be almost the same as it was before. Now that quite clearly isn't going to be true here."

He added: "I must say that I do not feel happy with the current intensity of building and I believe that we will all in time look at these [biodiversity net gain] indexes with a bit of knowledge and we will use them to try and reduce overdevelopment."

Midsomer Norton's Shaun Hughes agreed, adding that developers often saw the need for biodiversity net gain as an afterthought. He said: "The problem with moving it down the road is that it benefits neither the existing residents at this location or the future residents."

The developers will also invest £2.3m in the local area, including £130,000 on improvements to the Manor Road nature reserve and a £1.5m investment into public transport and liveable neighbourhoods. Council officers believe that these transport measures will reduce road usage by more than it would be increased by the additional traffic from the housing development.