Gelli Deg Gellideg, Merthyr Tydfil

House 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.

House prices and rents in Merthyr Tydfil

A typical home in Merthyr Tydfil cost £148,656 in August 2026, 1% less than a year before. That is 20% more than five years earlier and 60% more than ten years earlier.

Private renters in Merthyr Tydfil paid £754 a month on average in September 2026, 1.9% less than a year before. That is 44% more than five years earlier.

Sources: UK House Price Index (HM Land Registry, with the ONS and the Welsh Government), to August 2026; ONS Price Index of Private Rents, to September 2026. Figures for the whole council area, not this street. The typical price is adjusted for the mix of homes that sold, so it is not the value of any one home; the street's own sales are above. Rents are the average paid on all private tenancies, new and existing, so they move more slowly than rents being advertised.

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 July 2013 and some homes have none. Address data © Ordnance Survey and Royal Mail, shown for understanding the energy efficiency of buildings only.

5 homes with a current certificate; median floor area 55 m². Most common: House, mid-terrace (2); House, end-terrace (1); Bungalow, mid-terrace (1). Built: before 1900 (5). Tenure at assessment: rented (private) (2); owner-occupied (2).

Gas and electricity use

Homes with gas used 10,374 kWh of it on average in 2024, 14% less than the district's 12,118 kWh, and 2,773 kWh of electricity, about the same as the district. There are gas meters for about 100% of the homes.

These are all the homes on each postcode, whatever their size and however many live in them, so they show the kind of homes and heating here rather than what any one home uses. The typical figure is the median: half the homes used less. The district is CF48.

Source: Department for Energy Security and Net Zero, postcode level domestic gas and electricity statistics for 2024 (gas from mid-May to mid-May), Open Government Licence: domestic meters on each postcode, from the gas and electricity industry's meter readings. A postcode with fewer than 5 meters of a fuel has no figures for it.

Council tax

What each band costs in Merthyr Tydfil in 2026-27: Band D £2,594 a year on average, including the police and community council charges.

Homes by band in the neighbourhoods around this street: most are in band A (46% of about 2,360 homes).

Sources: Valuation Office Agency, Council Tax: stock of properties, homes at 31 March 2026 (counts rounded to the nearest 10; some small counts withheld), for the 3 neighbourhoods (census areas of about 700 homes each) 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: 5.
• Article 4 directions, tree preservation orders and green belt: Wales has no national record of these; the council's planning department holds them.

Listed buildings

• 15 Gelli-deg, grade II
• 16 Gelli-deg, grade II
• 17 Gelli-deg, grade II
• 19 Gelli-deg, grade II
• 21 Gelli-deg, grade II

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.

Energy projects nearby

2 energy projects near the street's postcodes, 1 of them not yet operating.

Planned projects can change or not go ahead; search the planning authority's applications by the reference shown for the plans, conditions and any objections. Construction brings traffic for some months; once built, solar farms and batteries are usually quiet, while turbines and waste plants can be seen or heard further away.

Source: Department for Energy Security and Net Zero, Renewable Energy Planning Database, Q2 2026 extract, Open Government Licence: renewable electricity and storage projects over 150 kW, operating, being built, permitted or applied for. Shown: wind turbines and plants that burn or digest waste within 5 km (3.1 miles), other projects of 1 MW or more within 2 km (1.2 miles); refused, withdrawn and abandoned projects are left out. Distances are from the nearest postcode centre to each project's grid reference.

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 75 address points in this street's postcodes, 7 at high risk, 10 at medium risk and 21 at low risk. Each counts once, at the higher of its rivers-and-sea and surface-water risk.

Rivers and the sea alone: 0 at high risk, 9 at medium risk and 11 at low risk. Surface water and small watercourses alone: 7 at high risk, 2 at medium risk and 10 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: at least one postcode centre is in flood zone 3. Zone 3 is a 1% (1 in 100) or greater annual chance of flooding from rivers, or 0.5% from the sea, ignoring defences. Welsh zones include an allowance for climate change.

Recorded floods

No recorded flood covers the centre of any of this street's postcodes.

Recorded floods are where floodwater was seen or surveyed after a flood. Many floods were never mapped, an outline over a postcode's centre does not mean every home in it flooded, and homes outside one may have. Ask the seller whether the home itself has flooded.

Sources: Natural Resources Wales Recorded Flood Extents; 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.

Coastal erosion

No projected coastal erosion zone is within 1 km (0.6 miles) of the street's postcodes.

Sources: Environment Agency, National Coastal Erosion Risk Mapping 2024 (England), and Natural Resources Wales, National Coastal Erosion Risk Management (Wales), Open Government Licence. Distances are from the nearest postcode centre to the edge of each zone; where a postcode centre is inside a zone, some homes on it may not be.

Storm overflows

No storm overflow outlet is within 1 km (0.6 miles) of the street's postcodes in this record, which covers the overflows reported to the Environment Agency: most of Wales's are reported to Natural Resources Wales instead.

Source: Environment Agency, Event Duration Monitoring storm overflow annual return for 2025, from the water companies' monitors on each overflow in England, Open Government Licence. Distances are from the nearest postcode centre to each overflow's outlet. A year's figures are published the following spring; a monitor that worked for less of the year undercounts.

Coal mining

3 of the street's 3 postcodes are in a coalfield, in a low risk area: coal was mined in the area, but no workings shallow enough to matter for building are recorded.

Conveyancers usually still order a coal mining search (CON29M) for a home in a coalfield.

Source: Mining Remediation Authority (formerly the Coal Authority), development high and low risk areas, Open Government Licence. Checked at each postcode's centre, so a home near the edge of an area may differ. It covers coal mining only, not other mining (such as tin, lead, iron or chalk), and is no substitute for a coal mining search. About the risk areas.

Radon

The highest radon potential in the 1 km squares around the street's postcodes is 5 to 10%: up to that share of homes there is estimated to be at or above the Action Level of 200 becquerels per cubic metre. At least part of that area is a radon Affected Area, where 1% or more of homes are.

Radon is a natural radioactive gas from the ground that can build up indoors; long exposure raises the risk of lung cancer. A three-month test with two small detectors is the only way to know a home's level, and a high level can usually be brought down with a sump or better ventilation. Homes built here in recent decades should have radon protection under the building regulations (basic protection from 3%, full protection from 10%). UKHSA sells a radon report for a single address from its detailed map at ukradon.org.

Source: British Geological Survey and UK Health Security Agency, Indicative Atlas of Radon in Great Britain, Open Government Licence. Contains British Geological Survey materials © UKRI 2026. Each 1 km square is classed by the highest radon potential found anywhere in it, so a square's figure can overstate it for much of the square; the detailed map is not open data.

Historic landfill

No historic landfill site is within 500 m (0.3 miles) of the street's postcodes.

Sources: Environment Agency and Natural Resources Wales, historic landfill sites (places where waste was put into or onto the land and no environmental permit is now in force), Open Government Licence. Distances are from the nearest postcode centre to the edge of each site as mapped; the outlines and dates come from old records and can be approximate. Landfill still operating is not included.

Height above sea level

The street's 21 addresses are between 179 m and 226 m above sea level (217 m on average); the ground rises about 47 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. Ratings and care homes: Care Quality Commission, latest ratings as at 2 November 2026 (England only; the CQC does not rate dental practices, and Wales's inspectorates give no ratings). 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.

Within 800 m (0.5 miles): 2 parks and gardens, 57 hectares in all.

Landmarks

The nearest historic landmark is Remains of Blast Furnaces, Cyfarthfa Ironworks, a scheduled monument, 390 m east. 45 listed buildings are within 1 km (0.6 miles), 2 of them Grade I and 3 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.

19 of the street's 21 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 Merthyr Tydfil: see them on the Merthyr Tydfil 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.

Exam results are from the Department for Education's school performance tables (Explore Education Statistics, Open Government Licence), for all pupils at each school. The middle school in England had 63% at the expected standard at the end of primary school (2025), Attainment 8 of 46.0 at GCSE (2026) and an A level average of C+ (2025). Attainment 8 adds up a pupil's grades in eight GCSEs, with English and maths counted twice (90 is the most), averaged over the school's pupils. Progress 8 compares pupils with others who had the same results at the end of primary school; it is not published for GCSEs in 2025 and 2026, as those pupils sat no primary tests during the pandemic. Small year groups swing from year to year, and figures for very small ones are withheld. Wales publishes no school results tables.

Nurseries and childcare

Ofsted registers childcare in England only. In Wales, nurseries, playgroups and childminders are registered and inspected by Care Inspectorate Wales, whose directory of services lists them with their reports.

Food hygiene ratings nearby

Source: Food Standards Agency, Food Hygiene Rating Scheme, extract of 4 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 Shopping Area (108); On or near Erw Las (17); On or near Heol Parc Maen (17).

Road safety

Source: Department for Transport, road safety data (STATS19), collisions in 2021 to 2025, as published by November 2026. Collisions in which someone was hurt and which were reported to the police, within 150 m of the middle of any of this street's postcodes, or of the street. Severity is the worst injury as the police recorded it.

2 collisions in which someone was hurt were reported on and around the street in 2021 to 2025: 0 fatal, 0 serious and 2 slight. Most were on roads with a 30 mph limit.

Only collisions in which someone was hurt and which the police were told about are here: damage-only collisions and near misses are not, and some injuries are never reported. Positions are recorded by the police, usually to within a few metres. Each year's figures are published the following September.

Traffic on nearby roads

The busiest counted road within 500 m (0.3 miles) is the A4102 between A470(T) and A4054, with 10,834 motor vehicles a day on average in 2025, 310 m from the street's postcodes.

Each figure is the annual average daily flow: the motor vehicles passing the count point, both ways, on an average day of the year. A point is counted by hand on a weekday every few years and estimated from the trend on similar roads in between. Lorries are heavy goods vehicles, as a share of all motor vehicles.

Source: Department for Transport, road traffic statistics, annual average daily flows to 2025, Open Government Licence. Distances are from the nearest postcode centre to each count point.

People and work

Source: ONS Census 2021, taken on 21 March 2021, for the 3 Output Areas (small census areas of about 125 households each) that this street's postcodes are in: 845 residents in 385 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 3 neighbourhoods around this street are in deciles 1 to 7 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.

• CF48 1ES: 14 addresses of 16 in the postcode
• CF48 1HT: 6 addresses of 37 in the postcode
• CF47 8PE: 1 address of 21 in the postcode

Nearby streets

Erw Las · Heol Tai Mawr · A470 · Maen Dy · Heol Parc Maen · Tai Mawr Way · A470 · Heol Lansbury · Tramroadside · A470

All the streets in CF47, CF48 and across Merthyr Tydfil.