Sprawling new-build suburbs on the outskirts of Sydney are sold on the promise of tomorrow - but the reality of today often falls far short for homebuyers moving in.

Thousands of families are snapping up high-density $1million dream homes in massive developments in areas like Marsden Park, Schofields and Oran Park.

But the homes are often being built faster than the infrastructure to support them, leaving locals without key services like trains, schools, shops, restaurants and child care.

The motto of Oran Park, 70km south-west of Sydney's CBD, is 'Growing today for your tomorrow' - but when 'tomorrow' exactly is seems vague. 

'They said we were going to get a train station in 2025 when we bought our home three years ago,' Oran Park mother Harmeet Kaur told Daily Mail Australia.

'We absolutely need a train service, but I don't know where we are going to get it because we don't see any progress.'

The nearest train station linking Oran Park to Sydney is currently 14km away in Leppington. 

The new-build housing developments offer families a dream home for a reasonable price - but the cost comes with limited infrastructure... and usually a long way from city centres.

Just $1million will buy you an Oran Park house worth $4-5million in other parts of Sydney, boasting four bedrooms, an in-ground pool, lounge rooms and dens, a cutting edge open-plan kitchen and even a theatre media room.

But the downside is being 70km from Sydney's CBD and limited public transport options, few Uber Eats options, restaurants and shops.

Developer Stockland tells prospective buyers at their new Lakeside development bordering Oran Park: 'Don't get locked out of tomorrow. Lock in your future today.' 

Over a tranquil photograph of rural countryside, it promises 'a pocket of calm in the centre of it all' but insists it's just 'just a stone's throw away from transport links, schools and retail for that balanced lifestyle'.

But it refers to current infrastructure like Gledswood Hills public school - with no plans for extra school facilities to cope with the new residents.

NSW state government has earmarked a spot for Oran Park's metro rail station, but there's still no timeline for it ever being built or when services will start.

The development is built on the site of the former Oran Park racetrack with streets named after stars of Australian motorsport like Peter Brock and Craig Lowndes.

And cars are absolutely vital for locals, with no trains and just a few buses each hour, which only go to nearby Campbelltown, Minto and Leppington.

'The bus services don't go anywhere,' said mother-of-five Ash Kettley, 30.

'You've got to catch two or three buses to get to one location and by that time you have been on a bus for two hours.

'You might have an appointment that goes for half an hour but you have to travel two hours to get there and back.'

Local road systems are also unable to cope with the sudden influx in new residents, with bottlenecks and choked roads at rush hour.

Oran Park has a wide dual carriageway running through it, but still suffers gridlock at school times when the main road in and out to Sydney grinds to a halt.

The single-carriageway Hermitage Way - which links the area with the M31 motorway - is brought to a standstill at a roundabout outside Gledswood Hills Public School, with traffic backed up in all directions.

It's even worse at Marsden Park, 50km, north-west of Sydney's CBD, where a series of developments all feed into Richmond Road, causing peak hour chaos.

'It's always congested,' local grandmother Linda Thow told Daily Mail Australia.

'Monday to Sunday, it's always busy. 

'Everybody is using it - they've tried asking people in the nearby suburbs to try using alternative routes but everybody comes this way to take kids to school or go to work.

'It takes ages to get anywhere.'

Marsden Park came under fire in 2015 when families first moved into the area to discover there were no schools for their children, green spaces, shops or trains stations.

In the years that followed, the infrastructure finally starting catching up with trains, schools and shopping centres reaching the area in 2021.

In Marsden Park and Schofields, homes were built with black roofs to meet insulation requirements in winter - but caused an internal heat surge in summer.

Most homes have air conditioning built in - but the buildings are so close together, the heat pumps of neighbouring homes blow into each other.

'They definitely needed to build with more space between the homes,' said Schofields IT worker Sethil Nathan, 37. 

'Even adding solar to your roof reduces your electricity bill, but adds to the heat in the house so you have to use your air-conditioning even more.

'It might be pocket-friendly, but it's not environmentally friendly.' 

Neighbour Monica Patel, 37, who owns a shop in ritzy Mosman on Sydney's north shore, says her family simply throws opens the doors and windows to keep cool in summer. 

'You don't need the air-conditioning when there's a breeze,' she said.

Even Oran Park - which has avoided many of the mistakes made in other suburbs -  is buckling under the weight of the sudden influx of young couples and new families.

Schools are already close to full - with one already having nine kindergarten classes - and child care services can't cope with the numbers.

'It's very family-friendly, but we need more before and after-school care,' said Ms Kettley. 

'Both the local schools' before and after-school care is full - and they're the only two in Oran Park. As a mother you can't do anything without that care facility.

YouTube channel Building Beautifully has railed against the developments shooting up on Sydney's periphery without enough planning. 

'With Sydney growing by up to 200,000 people every year, the state government is frantically opening up the outskirts of Western Sydney to developers,' warns town planning blogger Sharath Mahendran. 

'Houses are being built at lightning speed. But the rest of it the roads, the schools the supermarkets, the basic necessities, the transport - they're being left to the state government.

'And that's a problem because they're not keeping up. It's called urban sprawl - and it's a devil.'

He added: 'Development should not drive infrastructure - they should be coming first. 

'Infrastructure lag crippled Marsden Park for years. It's only just beginning to recover and even so it could take years before it's a properly established truly accessible town.'

'You would think it was a licence to print money but apparently not. It's just so hard - for a family-friendly environment, the lack of child care is just a joke.'

Shops are also currently limited with the Podium shopping centre offering a Woolworths and a handful of smaller shops and cafes while a second stage is under construction.

But locals have to drive out the area for a wider range of clothes shops, fresh fruit and veg or specialist food shops, homewares, eateries - and even take away restaurants.

But unlike some other new developments, Oran Park has been built with trees and small parkland areas dotted throughout.

'I have green spaces in front of me,' said skin therapist Evelyn Agostino, 23.

'It's greenery everywhere. 

'I love it. I moved here because I fell in love with the area and the new-build homes - but we can definitely do with more shops.'

But for all the drawbacks, those spoken to by Daily Mail Australia were pleased with their decision to move to the new-build suburbs.

'When we first moved in, there was a crime wave of cars being stolen and homes being broken into - but one person was arrested and it stopped immediately, said Samantha Prodromou, 28.

'We watched a video about the area before moving here and contacted the local pastor. It seemed like a really nice, community-focused place.

'What really drew us was the up-and-coming nature of it, but it's going to get better and better.'

For some though, it's up-and-coming too quickly though. 

Ms Kettley says in the six years she's lived in the area, fields of cows, horses and even pigs have been replaced by new homes already. 

'The kids used to love seeing the farm animals and we loved the farmland,' she said. 

'It really created a break from the rest of Sydney. 

'It's growing so fast. No-one anticipated for it to be growing as fast as it has in Oran Park - that's the reality of it.'