Cil Isaf Caernarfon, Gwynedd

Sales on this street

Source: HM Land Registry Price Paid Data, sales registered up to 28 August 2026, loaded 28 October 2026. Sales reach the register two weeks to two months after completion, so the last two months are incomplete. Matched by postcode and street name.

No sales recorded on this street since January 1995 under this street name.

Energy performance certificates

Source: Energy Performance of Buildings Register (MHCLG), register as at 1 November 2026. Latest certificate per address; certificates last ten years, so the oldest here dates from September 2013 and some homes have none. Address data © Ordnance Survey and Royal Mail, shown for understanding the energy efficiency of buildings only.

15 homes with a current certificate; median floor area 75 m². Most common: House, mid-terrace (9); House, semi-detached (3); House, end-terrace (3). Built: 1900-1929 (9); 1950-1966 (4); 1930-1949 (2). Tenure at assessment: rented (social) (15).

Council tax

What each band costs in Gwynedd in 2026-27: Band D £2,469 a year on average, including the police and community council charges.

Homes by band in the neighbourhood around this street: most are in band B (55% of about 1,130 homes).

Sources: Valuation Office Agency, Council Tax: stock of properties, homes at 31 March 2026 (counts rounded to the nearest 10), for the neighbourhood (census area of about 700 homes) around it, not just this street; Welsh Government, council tax levels 2026-27. Bands are charged as fixed shares of Band D; the actual bill depends on the parish and on discounts such as the single-person discount. Check a home's own band with the official council tax band checker.

Planning and heritage

• Conservation area: no postcode centre in this street's postcodes is in one.
• Listed buildings on or by this street: none.
• Article 4 directions, tree preservation orders and green belt: Wales has no national record of these; the council's planning department holds them.

Source: DataMapWales (Welsh Government): conservation areas compiled from the councils, and Cadw's listed buildings. Conservation areas are checked at each postcode's centre; some councils' boundaries in this layer have not been updated for years, so the council's own map is the one to rely on. Listed buildings are counted on or by this street. Planning applications are not here: there is no national open record of them.

Roadworks

Street works permits come from the Department for Transport's Street Manager, which covers England only.

Source: Department for Transport, Street Manager open data, permits and works up to 31 October 2026. It is published once a month, so works arranged or started since then are not shown, and dates are the ones planned unless the works have started or finished. Emergency works are often permitted after they begin.

Flood risk

Rivers, the sea or surface water: of the 141 address points in this street's postcodes, 0 at high risk, 0 at medium risk and 1 at low risk. Each counts once, at the higher of its rivers-and-sea and surface-water risk.

Rivers and the sea alone: none is in an area at risk. Surface water and small watercourses alone: 0 at high risk, 0 at medium risk and 1 at low risk.

High: 3.3% (1 in 30) or more chance of flooding a year. Medium: 1% to 3.3%. Low: 0.1% to 1%. The map allows for flood defences. Address points are every property record (UPRN) in the postcode, each counted if it is in an area or within 5 m of one (the maps stop at building walls); a few are not homes, such as garages, business units or caravan pitches. Counts cover whole postcodes, which can include other streets.

Flood zone for planning: no postcode centre on this street is in flood zone 2 or 3. Welsh zones include an allowance for climate change.

Sources: Natural Resources Wales Flood Risk Assessment Wales: rivers, sea and surface water (loaded 30 October 2026), and Flood Map for Planning: rivers and sea (loaded 29 October 2026); address points from OS Open UPRN and the ONS UPRN Directory. Flood zones are checked at each postcode's centre point. These are models of areas, which their publishers say are not suitable for showing whether an individual property is at risk, and they do not cover flooding from sewers or drains. Check an address on Natural Resources Wales's flood risk map.

Contains Natural Resources Wales information © Natural Resources Wales and database right. All rights reserved. Some features of this information are based on digital spatial data licensed from the UK Centre for Ecology & Hydrology © UKCEH. Defra, Met Office and DARD Rivers Agency © Crown copyright. © Cranfield University. © James Hutton Institute.

Height above sea level

The street's 24 addresses are between 35 m and 43 m above sea level (40 m on average); the ground rises about 8 m from the lowest to the highest.

Source: Ordnance Survey, OS Terrain 50, July 2026: the height of the ground on a 50 m grid, read at each address, in metres above Ordnance Datum (mean sea level at Newlyn). It is the lie of the land, not floor or threshold levels, and is accurate to a few metres. Being low-lying is not in itself a flood risk; the flood section above says what the flood maps show.

Broadband

Source: Ofcom Connected Nations, data as at January 2026. Percentages are of premises in each postcode that can get the service, not take-up or speed achieved.

Getting around

Sources: Department for Transport, NaPTAN (every public transport stop), as at 31 October 2026; Office of Rail and Road, Estimates of station usage 2024–25 (which stations are on the National Rail network, and their journeys: entries and exits in the year to March); OurAirports (public domain, kept by volunteers); car parks and charging points from Overture Maps Foundation, release 2026-10-21.0, which gathers business listings from Meta, Microsoft, Foursquare and others: not an official register, so some will be missing, private or out of date. Distances are straight lines from the middle of the street, not routes, and say nothing about how often anything runs. Stations opened since the end of ORR's year appear when ORR publishes the next one, each December; heritage railways are left out.

Local services

Sources: NHS Organisation Data Service, as at 31 October 2026: GP practices, community pharmacies and dental practices with an NHS contract, open now, each placed at the centre of its postcode; hospitals are NHS trust and Welsh health board sites named as hospitals, and may not have an emergency department. Police stations and cash machines from Overture Maps Foundation, release 2026-10-21.0, which gathers business listings: not an official register, so some will be missing or out of date. Distances are straight lines from the middle of the street. Nothing here says whether a practice is taking new patients or a dentist new NHS patients.

Parks and green space

Source: Ordnance Survey, OS Open Greenspace, April 2026: public parks and gardens, play spaces, playing fields and allotments, with their entrances. Distances are straight lines from the middle of the street to a site's nearest entrance (or its edge where none is recorded), not walking routes; sizes are the area OS maps for each site. Some sites, such as school playing fields, may not be open to the public.

Landmarks

The nearest historic landmark is Segontium Roman Fort, a scheduled monument, 250 m south-west. 247 listed buildings are within 1 km (0.6 miles), 7 of them Grade I and 12 of them Grade II*.

Sources: Historic England's registers through planning.data.gov.uk (MHCLG), and Cadw through DataMapWales (Welsh Government): World Heritage Sites within 10 km (6.2 miles), battlefields within 5 km (3.1 miles), registered parks and gardens within 3 km (1.9 miles), scheduled monuments within 2 km (1.2 miles), and Grade I and II* listed buildings within 1 km (0.6 miles). Ordnance Survey, OS Open Names, October 2026: named hills, valleys, lakes, woods, wetlands and coast (it has no rivers). Distances are in a straight line to the middle of each site, and being on a register does not mean there is public access.

Air quality

Source: Defra, modelled background air pollution, annual means for 2024, for the 1 km square that holds the middle of the street. These are background levels, away from the kerb: beside a busy road nitrogen dioxide in particular can be several times higher. UK limits are the legal annual limits for England and Wales; the World Health Organization's 2021 guidelines are much stricter, and most towns and cities are above them.

All three are within both the UK limits and the WHO guidelines.

Road and rail noise

Source: Welsh Government, Environmental Noise Mapping 2022 (Wales), modelled with Defra's noise model for every road and railway in Wales and published in August 2023, through DataMapWales: Lden, the average sound level over a whole day with extra weight for the evening and night, on a 10 m grid, read at each address. These are models of traffic, not measurements; they leave out aircraft, industry and neighbours, and a room at the back of a house is often much quieter than the front. The World Health Organization's guidelines are 53 dB for road traffic and 54 dB for railways.

2 of the street's 24 addresses are modelled at 55 dB or more from road traffic, above the WHO guidelines.

Climate, daylight and earthquakes

Monthly temperatures and rainfall, sunrise and sunset through the year, and earthquakes recorded nearby since 1970 are much the same across the area, so they are worked out once for Gwynedd: see them on the Gwynedd page.

Nearest schools

Source: Welsh Government address list of schools in Wales, October 2026 (maintained schools only, placed at their postcode). Distances are straight lines from the middle of the street to the school; catchments and admissions are not shown. Estyn, which inspects Welsh schools, no longer gives grades; its reports describe each school in words.

Food hygiene ratings nearby

Source: Food Standards Agency, Food Hygiene Rating Scheme, extract of 3 November 2026. Each rating is shown with the date it was given; a business may have been re-inspected since the extract. Within 500 m (0.3 miles) of the middle of the street.

Crime within 250 m

Source: data.police.uk street-level crime, September 2025 to August 2026. Police forces move every crime to the nearest of about 760,000 anonymised map points before publishing, so these are crimes near this street, not on it, and a busy point can collect crimes from a wider area. Counts are of records, not convictions.

Most of these are attached to: On or near Cae'R Saint (31); On or near Parking Area (29); On or near Pendalar (25); On or near Cil Isaf (22); On or near Cil Peblig (21).

People and work

Source: ONS Census 2021, taken on 21 March 2021, for the 2 Output Areas (small census areas of about 125 households each) that this street's postcodes are in: 644 residents in 251 households. The census was taken during a lockdown, so working from home is high and travel to work low compared with now. ONS swaps a few records between neighbouring areas and adds small amounts of noise to counts to protect privacy, so small differences mean little. Industry is not published for areas this small.

Who lives here

Homes

Work and commuting

Education and languages

Deprivation

The neighbourhood around this street is in decile 1 of 10 on the Welsh Index of Multiple Deprivation 2025, where 1 is the most deprived tenth of Wales's 1,917 neighbourhoods and 10 the least.

Source: Welsh Index of Multiple Deprivation 2025 (Welsh Government), by LSOA (about 1,500 people), through the ONS Postcode Directory. The index combines income, employment, health, education, crime, housing and living environment; it ranks areas against each other and does not describe any one household. Ranks in England and Wales are worked out separately and cannot be compared.

What has changed

Nothing new since the change feed started on 30 October 2026. New sales and energy certificates, and hygiene ratings, school inspections and flood figures nearby, will be listed here as the sources update.

Everything that has changed on and near this street

Postcodes on this street

Source: ONS Postcode Directory August 2026, ONS UPRN Directory September 2026, OS Open Linked Identifiers September 2026. A postcode can cover more than one street; the share shows how many of its addresses are on this one.

• LL55 2DN: 22 addresses of 23 in the postcode
• LL55 2DF: 1 address of 68 in the postcode
• LL55 2DL: 1 address of 50 in the postcode

Nearby streets

Lon Nant · Lon Cwrt Segontiwn · Cae'r Saint · Pendalar · Ffordd Ysgubor Goch · Cil Peblig · Lon y Bryn · Lon Nant · Llys Arfon · Cefn Talar · Lon Ysgol Rad · Hyfrydle

All the streets in LL55 and across Gwynedd.