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Frequently asked questions
LARGE-SCALE roofing WORKS
Do I need a bat survey before starting roof repairs?
It’s highly recommended. Bats roost in roof spaces and under roof tiles, and all UK bat species are strictly protected (including from disturbance). Before roof replacement or repair an Ecological Consultant should complete a Preliminary Roost Assessment (PRA) to check for bats or bat roosting potential. This avoids the risk of disturbing a bat or destroying a roost, which is a criminal offence and can put a handbrake on your programme.
Proactively conducting bat surveys can de-risk your programme. Unlike lesser consultants, we apply the correct and most efficient survey methodology with clear, concise and colour-coded reporting to get your project moving.
What is a ‘STAGE 1’ Preliminary Roost Assessment (PRA) and when is it required?
A PRA represents ‘Stage 1’ of the bat survey process for large-scale housing works. An Ecological Consultant carries out a detailed external inspection of each dwelling utilising drones, binoculars and a high-powered torch. Potential Roosting Features (PRFs) including raised roof tiles, damaged soffit boxes and missing mortar are digitally recorded. Fresh signs of bats, including: droppings, staining and feeding remains are also searched for. This assessment can be undertaken at anytime of the year.
Based on these findings and relevant contextual information e.g. the suitability of the surrounding landscape (e.g. urban, rural) each dwelling is assigned a low, medium or high classification following Bat Conservation Trust guidelines. This classification directly influences the recommended number of ‘Stage 2’ dusk emergence surveys that should be conducted at each dwelling. Low = 1 survey visit; Medium = 2 survey visits and High = 3 survey visits.
A Dusk Emergence Survey represents ‘Stage 2’ of the bat survey process for large-scale housing works. Ecological Consultants equipped with thermal and infra-red cameras (Night Vision Aids) are positioned at strategic points around each dwelling with the express objective of recording (or ruling out) bats emerging from the structure. Specialised bat detectors decode echolocation calls to identify species. The optimum survey window for dusk emergence survey is between May and September, inclusive.
The number of survey visits required at each dwelling is determined by the risk classification assigned during the Stage 1 assessment — one visit for low-risk dwellings, two for medium-risk, and three for high-risk — ensuring the level of survey effort is proportionate to the likelihood of bats being present. Where roosting bats have been ruled out, we will communicate this within 48 hours to remove any blockers to programme.
What IS A ‘STAGE 2’ DUSK EMERGENCE SURVEY?
Do nesting birds affect roofing or maintenance programmes?
Yes. All wild birds, their active nests and eggs are protected under the Wildlife and Countryside Act 1981. This can affect maintenance works such as stripping roof tiles, replacing fascias and soffit boxes or clearing gutters.
The core nesting bird season typically runs from March to August, inclusive, though some birds (particularly feral pigeon) can nest all year round. Timing the work can be an effective tool to avoid this risk, however, our comprehensive survey methodology accounts for bats as well as nesting birds and can be conducted at anytime of the year.
what if MY roofing operations have already started?
Don't worry — this is more common than you might think. Even if roofing or housing maintenance works have already commenced on site, we can still carry out a Stage 1 Preliminary Roost Assessment for your project. We can attend site within five working days, meaning there's no need to pause your programme or lose valuable time on site.
Following our inspection, we'll provide you with our high-level findings within 24 hours — clearly identifying which dwellings you can continue with immediately, and which should be moved to the end of the programme. This allows your teams to keep moving while ensuring the necessary ecological due diligence is in place.
help! I found a protected species on site
I found a newt on my site — do I need to stop works?
Pausing the works in that particular area on site is a sensible first step; importantly, we need to understand which newt species we are dealing with. The UK has three species of newt: great crested, smooth and palmate. Take a clear photograph and send it to us for prompt identification and advice.
Smooth and palmate newts are not strictly protected, instead they should be considered in a wider policy sense i.e. conserved and enhanced as per the national policy documents like the NPPF. For this reason, it’s unlikely works on site should be meaningfully affected.
Great crested newt confirmed on site, do however, represent a significant ecological constraint and it is advisable to pause works in that area and consult an Ecological Consultant on how best to proceed.
I found a mammal burrow on my site — what do I need to do?
Pause works within 30m of the burrow (particularly heavy plant, machinery and earthworks) until further assessments have been undertaken.
The high-risk scenario is a badger sett, which is protected under the Protection of Badgers Act 1992. Other occupied burrows also need care because wild mammals (e.g. fox and rabbit) are protected from crushing and asphyxiation. The solution: we deploy camera traps outside each burrow, typically left in place for a minimum of 48 hours. We can then determine the occupying species and advise how best to proceed.
How do you handle incidental discoveries of protected species during works?
If a protected species is found unexpectedly, pause works in the immediate area and contact an Ecological Consultant.
We can advise on any immediate precautions and attend site where needed. We will assess the issue, confirm what works can continue, and set out the steps needed to bring the affected area back on track.
What types of protected species could affect my construction project?
Protected species constraints typically include bats, great crested newt, badgers, nesting birds, water voles, otters and reptiles such as slow worms and grass snakes.
Nesting birds are the most common constraint when it comes to site clearance works. Birds can nest on buildings, open ground, trees and scrub which makes them a potential constraint on almost every development site.
Importantly, however, most nesting bird species are not protected from disturbance (only direct impacts) and therefore in most cases can be carefully worked around, rather than putting a handbrake on programme. Only birds listed on Schedule 1 of the Wildlife and Countryside Act 1981 are protected from disturbance. In either case, our Ecological Clerk of Works consultants can determine this for you and provide instant advice, allowing your works to proceed as quickly as possible.
great crested newt edna surveys
What is a great crested newt eDNA survey and when does it need to be carried out?
An eDNA survey is a Natural England-approved method for detecting great crested newt in ponds. Water samples are collected by our Environmental Consultants and analysed by an accredited laboratory for traces of newt DNA, making the method non-invasive and significantly faster than traditional survey methods.
The survey window is between 15th April to 30th June. If a pond lies within 500 metres of your site, it should be assessed for the risk of great crested newt.
Can a great crested newt eDNA survey be carried out outside the April to June window?
Technically yes, but outside the 15th April to 30th June window eDNA can only confirm presence, not absence. This is based on Natural Englands guidelines.
A positive result is still useful because it allows for clearer decision making. Even under a scenario where the pond has tested positive for great crested newt DNA there are solutions that can be immediately actioned, like District Level Licencing (DLL), however this is subject to specific geographic regions. We can advise you if you project is eligible for this scheme.
On-site ecological supervision and support
What is an Ecological Clerk of Works (ECoW) and do I need one?
An Ecological Clerk of Works is a qualified ecological consultant who typically attends site during the construction or clearance phase to advise operatives on the appropriate methods and processes that must be followed and advise all site personnel what to do if protected species are encountered. The added benefit of an ECoW is they can provide instant advice based on the dynamic nature of development sites, allowing works to proceed as quickly as possible whilst avoiding contravention of wildlife legislation.
An ECoW is often required via a planning or licence condition, however, clients often request ECoW guidance to de-risk projects and provide and additional layer of certainty when dealing with impactful works.
Do I need an ecologist on site during demolition or site clearance?
It’s highly recommended. Demolition and clearance are high-risk activities because buildings may support bats or nesting birds. Earthworks can directly affect reptiles, hedgehog, badgers, water voles and several other protected species.
Typically these potential risks are quantified during some form of baseline ecological assessment, however, this is not always the case. If you’re unsure, contact us and we can advise you. We can typically mobilise within five working days, with short-notice support available.
Can you help obtain a protected species licence for my project?
Yes. If protected species are confirmed and works are unavoidable, an European Protected Species (EPS) Licence from Natural England may be required before works can lawfully proceed.
We manage the licence process, including production of method statements, mitigation plans, supporting survey data and submission.
How quickly can you mobilise for an ecological survey?
We aim to respond to new enquiries within 24 hours and can typically attend site within five working days of instruction.
For urgent situations, such as live works discoveries, imminent planning deadlines or contractor mobilisation, contact us directly and we will be clear about what is achievable.
legislation, technology & Invasive plant species
What wildlife legislation applies to development projects in the UK?
Key legislation includes the Wildlife and Countryside Act 1981, the Conservation of Habitats and Species Regulations 2017, the Protection of Badgers Act 1992, the Wild Mammals (Protection) Act 1996 and the Environment Act 2021.
Together, these protect species such as bats, great crested newt, nesting birds, water voles, otters, badgers and wider biodiversity interests, including Biodiversity Net Gain for many developments in England. We provide straightforward advice on what applies to your project and what it means in practice.
What technology do you use for ecological surveys — drones, thermal imaging?
We use advanced survey technology where it creates more robust data or to speed up a process. Thermal imaging cameras support bat emergence surveys and roost characterisation; when coupled with drones, multiple buildings can be targeted simultaneously. Moreover, drones (used during the day) can assist with habitat mapping and accessing unsafe structures.
eDNA sampling is most commonly used for great crested newt surveys, however this method can be extended to other species, including invasive aquatic species. Moreover, DNA analysis of samples from terrestrial organisms e.g. suspected barn owl pellets, can be used to fast-track and complement traditional survey methodologies for determining presence or likely absence of a particular protected species.
How do i deal with invasive plant species on my site?
Invasive non-native species such as Japanese knotweed, Himalayan balsam and giant hogweed can spread during construction if not identified early in the development process. It is an offence under the Wildlife and Countryside Act 1981 and/or the Invasive Alien Species Order 2019 to allow these species to spread into the wild. What’s important to note is that the ‘wild’ is not your development site or neighbours backyard, rather it’s waterways, designated sites and other natural habitats.
A targeted INNS survey can be undertaken by our Environmental Consultants to identify each species and map their extent for eradication. Options include herbicide, excavation and licensed disposal. Early identification before ground disturbance helps avoid major remediation costs and delays.