1) What is alternative evidence?
Alternative evidence may be used as an alternative to site visits by Midlothian Building Standards.
Alternative evidence is accepted solely with prior agreement from Midlothian Building Standards.
Acceptance of alternative evidence by Midlothian Building Standards does not vouchsafe for any of the work detailed
in an alternative evidence submission. The supervision of the building operations and the quality of the completed
work is not the responsibility of Midlothian Council. Applicants are advised to seek independent professional advice.
2) Installation of drainage
a) By submitting this drainage alternative evidence, the person signing this document is confirming that the drainage installation
complies with the manufacturers’ recommendations and guidance, the relevant British Standards or European Standards, and the
Building (Scotland) Regulations 2004, as amended.
b) In practical terms, the person signing this document is confirming the suitability (where relevant) of the following:
1) materials used, including suitability of pipework for above ground use/exposure to sunlight, or for below ground use/resistance to
2) drainage layout, including provision of manholes, inspection chambers, accessible rodding eyes, traps, pop ups, handhole
access, gutters, downpipes, gratings, suitable support and connections,
3) depth and fall of drainage lines,
4) bedding to drainage lines,
5) backfill to drainage lines, and
6) protection to drainage lines (for example, 50mm concrete screed provided where 600mm cover to new drainage was not
achieved), and protection of drains passing through the underbuilding (using lintels or sleeving).
c) Where a public sewer has been built over, or has been connected to, or has been diverted, the person signing this document
confirms that Scottish Water consent has been sought and obtained.
3) Testing of drainage
Testing is usually in the form of an air test undertaken in accordance with the relevant British Standards. An open test (O/T) is undertaken
with the drainage bedded but the trench not backfilled. A final test (F/T) is undertaken on the completed drainage installation, with all
sanitary fittings installed. Only where testing is not possible due to the configuration of the existing drainage, a visual inspection of the
drainage is undertaken to confirm a satisfactory installation.
4) Guidance on providing drainage layout drawing
Copies of the as-installed drainage layouts are required for our drainage archive, which is available to the general public.
The following guidance should be used when preparing a drainage drawing:
a) The address and plot number (if relevant) should be added to the drawing.
b) All drainage removals to be indicated by a broken red line and explanatory text.
c) All existing drainage to be shown in black.
d) On all relevant areas of plans and elevations, all newly-installed foul water (FW) drainage to be shown in red and newly-installed
storm water (SW) drainage to be shown in blue.
e) If the drainage differs to the approved building warrant drainage drawings, the size and type of all newly-installed drainage
materials to be fully detailed, to include connections to existing drainage.
f) Show and detail all relevant existing and new drainage (including gutters, downpipes, foul and surface water drainage lines, traps,
rodding points/eyes, manholes, inspection chambers, direction of flow, etc.).
g) Each drainage line should be marked with the date of any test and Pass (see note 3).
5) Examples of marking-up drainage layout drawings
6) What next?
Please submit this form to the case surveyor at Midlothian Building Standards. The case surveyor will check if the information
provided is acceptable or if outstanding issues remain to be addressed. The case surveyor will then advise you if the submission is
acceptable or not.
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