Comedian Ricky Gervais’s plans to demolish and rebuild his riverside home in Marlow have been paused after a bat survey found a large colony roosting in the property and the Environment Agency raised fresh objections to the development’s flood-risk assessment.

The survey recorded more than 270 soprano pipistrelle bats emerging from the building and identified widespread droppings, prompting statutory protections under the Wildlife and Countryside Act. Work that would disturb or damage bat roosts requires a licence from Natural England and an approved mitigation strategy, and planning advisers say that could include creation of an alternative bat loft, provision of bat boxes and adherence to a bat mitigation strategy tailored for any maternity roost on site.

Local planning records show the presence of a maternity roost is especially significant because breeding bats tend to return to the same locations and have low reproductive rates, making colonies sensitive to disturbance. Under UK law it is an offence to intentionally or recklessly disturb, injure or kill any bat or to damage, destroy or obstruct access to bat roosts.

The bat findings add to a string of hurdles for Gervais, 64, whose proposals to replace the existing three-bedroom house with a larger neoclassical-style dwelling have previously been rejected and paused. A planning decision last September refused an earlier scheme on the grounds that it represented “inappropriate more vulnerable development in a high flood risk zone” and failed to demonstrate it would not increase flood risk. The applicant included CCTV images in that submission showing the property’s main entrance, garage and back garden underwater when the River Thames burst its banks.

The Environment Agency later lodged an objection to a resubmitted application, saying the flood-risk assessment did not comply with site-specific requirements and did not adequately take the impacts of climate change into account. An agency planning adviser wrote that, in the absence of an acceptable flood-risk assessment, the agency objected to the application and would be unlikely to grant the separate Flood Risk Activity Permit required to carry out works adjacent to the main river.

The agency recommended detailed measures, including flood resistance and resilience features such as physical barriers, raised electrical fittings and construction methods designed to reduce flood damage. It also said any revised submission would need to demonstrate that loss of floodplain storage and allowances for climate change could be compensated to prevent increasing flood risk elsewhere.

Gervais’s planning agent has said the project is on hold while clarification is sought from the Environment Agency. The agent argued the proposal would not increase flood water displacement because it would not enlarge the building footprint, and that the scheme would raise internal floor levels and increase below-ground flood storage to improve safety for occupiers. The agent also maintained the intention to deliver a dwelling with enhanced sustainability credentials and improved design quality compared with the existing house.

The Marlow property, bought by Gervais in 2014, has been the focus of a wider campaign by the comedian to replace what he has described as a modest country retreat. His portfolio includes other high-value properties, including a north London residence and apartments in New York, but planning documents in this case have focused on the site’s riverside location and repeated flooding incidents dating back decades.

Because bats are protected and the site lies alongside the River Thames, the applicant would need to secure both an appropriate wildlife licence and a Flood Risk Activity Permit before construction could begin. Local planning officers will also consider whether revised assessments meet national and local planning policy, including requirements to demonstrate that development will not increase flood risk and will deliver biodiversity net gain when loss of habitat is proposed.

At present, the combination of the bat survey findings and outstanding Environment Agency concerns means Gervais’s redevelopment plans remain paused pending further ecological and flood-risk work and any subsequent licensing or permits that may be required.